Multi-link establishment method and communication apparatus

ABSTRACT

This application discloses a multi-link establishment method and a related device. A multi-link association response frame carries radio bitmap information, to indicate an AP allowed to be associated with a radio of a STA MLD or a link allowed to be established by using a radio of a STA MLD, so that the radio subsequently switches between different APs or links. The multi-link association response frame carries link establishment status information, to indicate a link establishment status of each link that the STA MLD requests to establish, so that multi-link establishment is more flexible. The multi-link association response frame carries reassociation information, to indicate whether each parameter in association configuration information is reserved, so that a problem that signaling overheads are relatively large due to a reassociation operation is avoided. It can be learned that, in the multi-link establishment method, the foregoing information is carried to improve multi-link establishment flexibility.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Application No.PCT/CN2021/104115, filed on Jul. 1, 2021, which claims priority toChinese Patent Application

No. 202010632127.0, filed on Jul. 3, 2020. The disclosures of theaforementioned applications are hereby incorporated by reference intheir entireties.

TECHNICAL FIELD

This application relates to the field of communication technologies, andin particular, to a multi-link establishment method and a communicationapparatus.

BACKGROUND

An IEEE 802.11ax next-generation wireless-fidelity (Wi-Fi), that is,extremely high throughput (EHT) device aggregates a plurality ofdiscontinuous links by using a multi-link cooperation technology, toform an ultra-high bandwidth. In addition to aggregating a higherbandwidth, the multi-link cooperation technology may further be used tosimultaneously send a data packet of a same service to a same station.It can be learned that the multi-link cooperation technology greatlyimproves a transmission rate.

A station multi-link device (STA MLD) may establish a plurality of linksto an access point multi-link device (AP MLD) by using one link. Amulti-link association request frame or a multi-link associationresponse frame in the multi-link establishment operation carriesinformation about the plurality of links, to establish the plurality oflinks.

Currently, for a single-link device, for example, a station (STA) and anaccess point (AP), in a process in which the STA associates with the AP,a status code field in an association response frame may be used toindicate whether the STA is successfully associated with the AP.However, for a multi-link device, if only the status code field is usedto indicate successful association between multi-link devices, aspecific establishment status of each link cannot be learned. As aresult, multi-link establishment flexibility is relatively low.

SUMMARY

A multi-link establishment method and a communication apparatus providedin this application help improve multi-link establishment flexibility.

According to a first aspect, this application discloses a multi-linkestablishment method. The method includes: A STA MLD sends a multi-linkassociation request frame; and the STA MLD receives a multi-linkassociation response frame, where the multi-link association responseframe carries radio bitmap information, and the radio bitmap informationis used to indicate a radio, allowed to be used to establish each linkthat the STA MLD requests to establish, of the STA MLD.

According to a second aspect, this application discloses a multi-linkestablishment method. The method corresponds to the first aspect, and isdescribed from a perspective of an AP MLD. The method includes: The APMLD receives a multi-link association request frame; and the AP MLDsends a multi-link association response frame, where the multi-linkassociation response frame carries radio bitmap information, and theradio bitmap information is used to indicate a radio, allowed to be usedto establish each link that a STA MLD requests to establish, of the STAMLD.

It can be learned that, both the multi-link establishment methodsdescribed in the two aspects help the AP MLD notify the STA MLD of theradio, allowed to be used to establish each link that the STA MLDrequests to establish, of the STA MLD. Further, this helps determine,when there is no radio allowed to be used for the link, that the linkfails to be established; or determine, when there is the radio allowedto be used for the link, that the link is successfully established. Whena same radio is allowed to be used to establish a plurality of links,the radio can perform fast link switching between the plurality oflinks, thereby avoiding a problem of a relatively long delay caused byreestablishing the link, and improving multi-link establishmentflexibility.

In other words, if the radio bitmap information indicates that a radio,allowed to be used to establish one link that the STA MLD requests toestablish, of the STA MLD does not exist or is zero, it implicitlyindicates that the link fails to be established. If the radio bitmapinformation indicates that there is one radio, allowed to be used toestablish one link that the STA MLD requests to establish, of the STAMLD, it implicitly indicates that the link is successfully established.If the radio bitmap information indicates that there are a plurality ofradios, allowed to be used to establish one link that the STA MLDrequests to establish, of the STA MLD, it implicitly indicates that thelink is successfully established, and the plurality of radios may allswitch to the link.

Optionally, if the radio bitmap information indicates that a same radioof the STA MLD is allowed to be used to establish a plurality of linksthat the STA MLD requests to establish, it implicitly indicates that theradio may be used to establish the plurality of links, and may performlink switching between the plurality of links. It can be learned that,in the multi-link establishment method, whether link establishmentsucceeds is indicated, and the plurality of links may further beestablished for the same radio, to help the radio perform fast switchingbetween the plurality of links, thereby avoiding a problem of arelatively large delay caused due to switching performed after a link issubsequently re-established.

The following describes optional implementations for the multi-linkestablishment methods described in the first aspect and the secondaspect.

Descriptions of the radio bitmap information may further include but arenot limited to the following types: The radio bitmap information is usedto indicate an AP that each radio of the STA MLD is allowed to beassociated with and that is in the AP MLD; or a link that is allowed toshare each radio of the STA MLD; or a link that each radio of the STAMLD is allowed to be used to establish; or a radio that each AP in theAP MLD is allowed to be associated with and that is of the STA MLD. Inthe several description manners, information such as whether each linkis successfully established, a plurality of links between which eachradio is allowed to switch, and whether a radio is available may also belearned. Details are not described herein.

In this implementation, the radio bitmap information indicates acorrespondence between each link and each radio of the STA MLD, or acorrespondence between each AP in the AP MLD and each radio of the STAMLD. Therefore, in this implementation, the radio bitmap information maybe carried in multi-link device information in a multi-link element.Optionally, the radio bitmap information may alternatively be carried inthe multi-link association response frame in a form of an independentfield.

In addition, a total quantity of bits occupied by the radio bitmapinformation=a product of a quantity of radios of the STA MLD and aquantity of APs in the AP MLD. Alternatively, a total quantity of bitsoccupied by the radio bitmap information=a product of a quantity ofradios of the STA MLD and a quantity of links that the STA MLD requeststo establish. It can be learned that radio quantity information carriedin the multi-link association request frame helps determine the quantityof bits of the radio bitmap information or a length of the radio bitmapinformation.

In this implementation, the radio bitmap information may be carried inthe MLD-level info in the multi-link element.

In another implementation, the multi-link association response framecarries a plurality of pieces of radio bitmap information, one piece ofradio bitmap information corresponds to one link that a STA MLD requeststo establish, and the radio bitmap information is used to indicate aradio, allowed to be used to establish the corresponding link, of theSTA MLD. It can be learned that this implementation helps the AP MLDnotify the STA MLD of the radio, allowed to be used to establish eachlink that the STA MLD requests to establish, of the STA MLD. Further, ifradio bitmap information of one link indicates that a radio, allowed tobe used, of the STA MLD does not exist or is zero, it implicitlyindicates that the link fails to be established. If radio bitmapinformation of one link indicates that there is one radio, allowed to beused, of the STA MLD, it implicitly indicates that the link issuccessfully established. If radio bitmap information of one linkindicates that there are a plurality of radios, allowed to be used, ofthe STA MLD, it implicitly indicates that the link is successfullyestablished, and the plurality of radios may all switch to the link.

Optionally, if radio bitmap information of a plurality of linksseparately indicates a same radio, allowed to be used, of the STA MLD,it implicitly indicates that the radio may be used to establish theplurality of links, and may perform link switching between the pluralityof links.

It can be learned that, in this implementation, whether linkestablishment succeeds is indicated, and the plurality of links mayfurther be established for the same radio, to help the radio performfast switching between the plurality of links, thereby avoiding aproblem of a relatively large delay caused due to switching performedafter a link is subsequently re-established.

In this implementation, a total quantity of bits occupied by radiobitmap information of one link=a quantity of radios of the STA MLD.

In this implementation, radio bitmap information of a transmitted linkthat the STA MLD requests to establish is carried in multi-link deviceinformation in a multi-link element; and radio bitmap information of anon-transmitted link that the STA MLD requests to establish is carriedin link configuration information of the non-transmitted link in themulti-link element. Alternatively, regardless of a transmitted link or anon-transmitted link, radio bitmap information of each link is carriedin multi-link device information in a multi-link element. Optionally,radio bitmap information of each link is carried in the multi-linkassociation response frame in a form of an independent field.

Optionally, the radio bitmap information in the foregoing implementationmay alternatively be carried in the multi-link association request frameor a reassociation request frame, to notify the AP MLD of acorrespondence between a radio requested by the STA MLD and a link, or acorrespondence between a radio and an AP. Details are not describedherein.

Optionally, the radio bitmap information in the foregoing implementationmay alternatively be carried in a reassociation response frame, tonotify the STA MLD of a correspondence between a radio allowed by the APMLD and a link, or a correspondence between a radio and an AP. Detailsare not described herein.

Optionally, the multi-link association request frame or thereassociation request frame further carries radio quantity information,and the radio quantity information is used to indicate a quantity ofradios of the STA MLD. Further, this helps determine a quantity of bitsof total radio bitmap information of all links or a length of totalradio bitmap information of all links, or helps determine a quantity ofbits of radio bitmap information of each link or a length of radiobitmap information of each link.

For the foregoing multi-link establishment method, the reassociationresponse frame received by the STA MLD from the AP MLD may carryreassociation information, and the reassociation information is used toindicate whether each parameter in association configuration informationis reserved. The AP MLD uses the reassociation information to enable theSTA MLD to reserve a part of parameters, so that repeated transmissionof the parameters in and after a reassociation operation can be avoided,thereby reducing signaling overheads.

Optionally, the association configuration information may beinformation, shared on a plurality of links, in a multi-link device. TheAP MLD uses the reassociation information to enable the STA MLD toreserve a part of parameters, so that repeated transmission of theparameters in and after a reassociation operation can be avoided,thereby reducing signaling overheads.

Optionally, the association configuration information includes but isnot limited to one or more of the following parameters: a blockacknowledgment protocol, a sequence number, a packet number, a duplicatedetection cache, a fragmentation and reassembly buffer, and a bufferedmedia access control service data unit MSDU.

In an implementation, the reassociation information includes one bit.The bit corresponds to all parameters in the association configurationinformation, and is used to indicate whether all the parameters in theassociation configuration information are reserved.

In another implementation, the reassociation information includes aplurality of bits. One bit corresponds to one parameter in theassociation configuration information, and is used to indicate whetherthe corresponding parameter is reserved.

In still another implementation, the reassociation information includesa plurality of bits. One bit corresponds to one or more parameters inthe association configuration information, and is used to indicatewhether the corresponding one or more parameters are reserved.

In still another implementation, the reassociation information includesa plurality of bits. One bit corresponds to a plurality of parameters inthe association configuration information, and is used to indicatewhether the corresponding plurality of parameters are reserved.

Optionally, the reassociation information is carried in multi-linkdevice information in a multi-link element in the reassociation responseframe. Alternatively, the reassociation information is carried in thereassociation response frame in a form of an independent field.

According to a third aspect, this application discloses a multi-linkestablishment method. The method includes: A STA MLD sends a multi-linkassociation request frame; and the STA MLD receives a multi-linkassociation response frame, where the multi-link association responseframe carries link establishment status information, and the linkestablishment status information is used to indicate a linkestablishment status of each link that the STA MLD requests toestablish. It can be learned that, in the multi-link establishmentmethod, the STA MLD may learn of the link establishment status of eachlink based on the link establishment status information, that is, a linkfails to be established is allowed to exist in the links that the STAMLD requests to establish, thereby improving multi-link establishmentflexibility.

According to a fourth aspect, this application discloses a multi-linkestablishment method. The method is described from a perspective of anAP MLD. The method includes: An AP MLD receives a multi-link associationrequest frame; and the AP MLD sends a multi-link association responseframe, where the multi-link association response frame carries linkestablishment status information, and the link establishment statusinformation is used to indicate a link establishment status of each linkthat a STA MLD requests to establish. It can be learned that, in themulti-link establishment method, the AP MLD may indicate the linkestablishment status of each link. A link fails to be established isallowed to exist in the links that the STA MLD requests to establish,thereby improving multi-link establishment flexibility.

The following describes optional implementations for the multi-linkestablishment methods described in the third aspect and the fourthaspect.

In an implementation, the link establishment status information includesa status code field and link configuration information of a successfullyestablished link in the links that the STA MLD requests to establish.The status code field is used to indicate that the STA MLD issuccessfully associated with the AP MLD. The AP MLD may use thisimplementation to enable the STA MLD to learn that a link whose linkconfiguration information is carried in the multi-link associationresponse frame is a successfully established link. A link fails to beestablished is allowed to exist in the links that the STA MLD requeststo establish, thereby improving multi-link establishment flexibility. Inaddition, the multi-link association response frame does not need tocarry link configuration information of a link that fails to beestablished. It can be learned that, in this implementation, signalingoverheads can further be reduced.

Optionally, if in this implementation, the status code field indicatesthat the STA MLD fails to be associated with the AP MLD, the multi-linkassociation response frame may not carry the link configurationinformation of the link.

In another implementation, the link establishment status informationincludes a status code field and link configuration information of asuccessfully established link in the links that the

STA MLD requests to establish. The status code field is used to indicatethat a part of the links that the STA MLD requests to establish aresuccessfully established. The AP MLD may use this implementation toenable the STA MLD to learn that a link whose link configurationinformation is carried in the multi-link association response frame is asuccessfully established link. A link fails to be established is allowedto exist in the links that the STA MLD requests to establish, therebyimproving multi-link establishment flexibility.

Optionally, the status code field indicates that all the links that theSTA MLD requests to establish are successfully established. The linkestablishment status information may include link configurationinformation of all the links that the STA MLD requests to establish.

In still another implementation, the link establishment statusinformation includes a status code field and link configurationinformation of a successfully established non-transmitted link in thelinks that the STA MLD requests to establish. The status code field isused to indicate that a transmitted link in the links that the STA MLDrequests to establish is successfully established. Optionally, when thestatus code field indicates that the transmitted link in the links thatthe STA MLD requests to establish fails to be established, the linkestablishment status information may further include link configurationinformation of the successfully established non-transmitted link in thelinks that the STA MLD requests to establish. It can be learned that, inthis implementation, a link fails to be established is allowed to existin the links that the STA MLD requests to establish, thereby improvingmulti-link establishment flexibility.

In the foregoing optional implementation, the status code field may becarried in the multi-link association response frame in a form of anindependent field, the link configuration information of thesuccessfully established transmitted link may be carried in multi-linkdevice information in a multi-link element in the multi-link associationresponse frame, and the link configuration information of thesuccessfully established non-transmitted link may be carried in the linkconfiguration information of each link in the multi-link element in themulti-link association response frame. Optionally, the status code fieldand the successfully established link may alternatively be carried inanother position in the multi-link association response frame.

In still another implementation, the link establishment statusinformation includes a plurality of status code fields. One status codefield corresponds to one link that the STA MLD requests to establish,and is used to indicate a link establishment status of the correspondinglink. It can be learned that, in this implementation, each linkcorresponds to one status code field. Not only whether the correspondinglink is successfully established may be indicated, to improve multi-linkestablishment flexibility, but another status of link establishment canalso be indicated.

In addition, a manner in which the link establishment status informationis carried in the multi-link association response frame includes but isnot limited to the following two types. In an implementation, in thelinks that the STA MLD requests to establish, a status code field of atransmitted link is carried in multi-link device information in amulti-link element, and a status code field of a non-transmitted link iscarried in link configuration information of the non-transmitted link inthe multi-link element. In another implementation, in the links that theSTA MLD requests to establish, status code fields of the links are allcarried in multi-link device information in a multi-link element.

In still another implementation, the link establishment statusinformation includes a status code field and link establishment statusbitmap information. The status code field is used to indicate that theSTA MLD is successfully associated with the AP MLD, and the linkestablishment status bitmap information is used to indicate whether eachlink that the STA MLD requests to establish is successfully established.Optionally, if the status code field indicates that the STA MLD fails tobe associated with the AP MLD, the link establishment status informationmay not carry the link establishment status bitmap information.

In still another implementation, the link establishment statusinformation includes a status code field and link establishment statusbitmap information. The status code field is used to indicate that apart of the links that the STA MLD requests to establish aresuccessfully established, and the link establishment status bitmapinformation is used to indicate whether each link that the STA MLDrequests to establish is successfully established. Optionally, if thestatus code field indicates that all the links that the STA MLD requeststo establish are successfully established, the link establishment statusinformation may not include the link establishment status bitmapinformation, or the link establishment status bitmap informationincluded in the link establishment status information is all 1 (It isassumed that when a value of a bit corresponding to a link is 1, itindicates that the link is successfully established.). Optionally, ifthe status code field indicates that all the links that the STA MLDrequests to establish fail to be established, the link establishmentstatus information may not include the link establishment status bitmapinformation, or the link establishment status bitmap informationincluded in the link establishment status information is all 0 (it isassumed that when a value of a bit corresponding to a link is 0, itindicates that the link fails to be established).

In still another implementation, the link establishment statusinformation includes a status code field and link establishment statusbitmap information. The status code field is used to indicate that atransmitted link in the links that the STA MLD requests to establish issuccessfully established, and the link establishment status bitmapinformation is used to indicate whether each non-transmitted link thatthe STA MLD requests to establish is successfully established.Optionally, if the status code field indicates that the transmitted linkin the links that the STA MLD requests to establish fails to beestablished, the link establishment status information may still includethe link establishment status bitmap information, to indicate whethereach non-transmitted link is successfully established.

Optionally, the link establishment status information may alternativelybe carried in a reassociation response frame, to indicate whether eachlink is successfully established in a reassociation process.

In addition, in the multi-link establishment method, the reassociationresponse frame may carry reassociation information, and thereassociation information is used to indicate whether each parameter inassociation configuration information is reserved. The associationconfiguration information includes but is not limited to one or more ofthe following parameters: a block acknowledgment protocol, a sequencenumber, a packet number, a duplicate detection cache, a fragmentationand reassembly buffer, and a buffered media access control service dataunit MSDU. Optionally, the association configuration information may beinformation, shared on a plurality of links, in a multi-link device. Thereassociation information is used to reserve a part of parameters, sothat repeated transmission of the parameters in and after areassociation operation can be avoided, thereby reducing signalingoverheads.

In an implementation, the reassociation information includes one bit.The bit corresponds to all parameters in the association configurationinformation, and is used to indicate whether all the parameters in theassociation configuration information are reserved.

In another implementation, the reassociation information includes aplurality of bits. One bit corresponds to one parameter in theassociation configuration information, and is used to indicate whetherthe corresponding parameter is reserved.

In still another implementation, the reassociation information includesa plurality of bits. One bit corresponds to one or more parameters inthe association configuration information, and is used to indicatewhether the corresponding one or more parameters are reserved.

In still another implementation, the reassociation information includesa plurality of bits. One bit corresponds to a plurality of parameters inthe association configuration information, and is used to indicatewhether the corresponding plurality of parameters are reserved.

Optionally, the reassociation information is carried in multi-linkdevice information in a multi-link element in the reassociation responseframe. Alternatively, the reassociation information is carried in thereassociation response frame in a form of an independent field.

In addition, in the multi-link establishment methods described in thefirst aspect and the second aspect, a manner of indicating thecorrespondence between a radio and a link and the correspondence betweena radio and an AP is used to notify the STA MLD of a successfullyestablished link and a link fails to be established. In the multi-linkestablishment methods described in the third aspect and the fourthaspect, the link establishment status of each link is indicated, tonotify the STA MLD of a successfully established link and a link failsto be established. It can be learned that, the multi-link establishmentmethods described in the first aspect and the second aspect and themulti-link establishment methods described in the third aspect and thefourth aspect need to resolve a same problem, have specific technicalfeatures with a same function, and achieve a beneficial effect of moreflexible multi-link establishment. Therefore, the multi-linkestablishment methods described in the first aspect and the secondaspect and the multi-link establishment methods described in the thirdaspect and the fourth aspect belong to a same inventive concept, andsatisfy a unity requirement.

According to a fifth aspect, this application further provides amulti-link establishment method. The method includes: A STA MLD sends areassociation request frame; and the STA MLD receives a reassociationresponse frame, where the reassociation response frame carriesreassociation information, and the reassociation information is used toindicate whether each parameter in association configuration informationis reserved. The reassociation information is used to reserve a part ofparameters, so that repeated transmission of the parameters in and aftera reassociation operation can be avoided in this method, therebyreducing signaling overheads.

According to a sixth aspect, this application further provides amulti-link establishment method. The method corresponds to the methoddescribed in the fifth aspect, and is described from a perspective of anAP MLD. The method includes: The AP MLD receives a reassociation requestframe; and the AP MLD sends a reassociation response frame, where thereassociation response frame carries reassociation information, and thereassociation information is used to indicate whether each parameter inassociation configuration information is reserved. The reassociationinformation is used to reserve a part of parameters, so that repeatedtransmission of the parameters in and after a reassociation operationcan be avoided in this method, thereby reducing signaling overheads.

The following describes optional implementations for the multi-linkestablishment methods described in the fifth aspect and the sixthaspect.

In an implementation, the association configuration information may beinformation, shared on a plurality of links, in a multi-link device. Thereassociation information is used to reserve a part of parameters, sothat repeated transmission of the parameters in and after areassociation operation can be avoided, thereby reducing signalingoverheads.

In another implementation, the association configuration informationincludes but is not limited to one or more of the following parameters:a block acknowledgment protocol, a sequence number, a packet number, aduplicate detection cache, a fragmentation and reassembly buffer, and abuffered media access control service data unit MSDU.

The reassociation information includes one or more bits. One bitcorresponds to one or more parameters in the association configurationinformation, and is used to indicate whether the corresponding one ormore parameters are reserved. In other words, the reassociationinformation includes but is not limited to the following optionalimplementations.

In an implementation, the reassociation information includes one bit.The bit corresponds to all parameters in the association configurationinformation, and is used to indicate whether all the parameters in theassociation configuration information are reserved.

In another implementation, the reassociation information includes aplurality of bits. One bit corresponds to one parameter in theassociation configuration information, and is used to indicate whetherthe corresponding parameter is reserved.

In still another implementation, the reassociation information includesa plurality of bits. One bit corresponds to one or more parameters inthe association configuration information, and is used to indicatewhether the corresponding one or more parameters are reserved.

In still another implementation, the reassociation information includesa plurality of bits. One bit corresponds to a plurality of parameters inthe association configuration information, and is used to indicatewhether the corresponding plurality of parameters are reserved.

Optionally, the reassociation information is carried in multi-linkdevice information in a multi-link element in the reassociation responseframe. Alternatively, the reassociation information is carried in thereassociation response frame in a form of an independent field.

In an implementation, a multi-link association response frame in the1^(st) association process between the AP MLD and the STA MLD or theforegoing described reassociation response frame further carries linkestablishment status information. The link establishment statusinformation is used to indicate a link establishment status of each linkthat the STA MLD requests to establish. It can be learned that, in themulti-link establishment method, the AP MLD may indicate the linkestablishment status of each link. A link fails to be established isallowed to exist in the links that the STA MLD requests to establish,thereby improving multi-link establishment flexibility.

For an optional implementation of the link establishment statusinformation, refer to the implementations described in the third aspectand the fourth aspect. Details are not described herein again.

In another implementation, a multi-link association response frame inthe 1^(st) association process between the AP MLD and the STA MLD or theforegoing described reassociation response frame further carries radiobitmap information. The radio bitmap information is used to indicate aradio, allowed to be used to establish each link that the STA MLDrequests to establish, of the STA MLD. It can be learned that thisimplementation helps enable the AP MLD to notify the STA MLD of theradio, allowed to be used to establish each link that the STA MLDrequests to establish, of the STA MLD.

Optionally, if the radio bitmap information indicates that a radio,allowed to be used to establish one link that the STA MLD requests toestablish, of the STA MLD does not exist or is zero, it implicitlyindicates that the link fails to be established. If the radio bitmapinformation indicates that there is one radio, allowed to be used toestablish one link that the STA MLD requests to establish, of the STAMLD, it implicitly indicates that the link is successfully established.If the radio bitmap information indicates that there are a plurality ofradios, allowed to be used to establish one link that the STA MLDrequests to establish, of the STA MLD, it implicitly indicates that thelink is successfully established, and the plurality of radios may allswitch to the link.

Optionally, if the radio bitmap information indicates that a same radioof the STA MLD is allowed to be used to establish a plurality of linksthat the STA MLD requests to establish, it implicitly indicates that theradio may be used to establish the plurality of links, and may performlink switching between the plurality of links. It can be learned that,in the multi-link establishment method, whether link establishmentsucceeds is indicated, and the plurality of links may further beestablished for the same radio, to help the radio perform fast switchingbetween the plurality of links, thereby avoiding a problem of arelatively large delay caused due to switching performed after a link issubsequently re-established.

For a possible description of the radio bitmap information, refer to thecontent described in the first aspect and the second aspect. Details arenot described herein again.

In another implementation, a multi-link association response frame inthe 1^(st) association process between the AP MLD and the STA MLD or theforegoing described reassociation response frame further carries aplurality of pieces of radio bitmap information, and one piece of radiobitmap information corresponds to one link that the STA MLD requests toestablish. In other words, the radio bitmap information is used toindicate a radio, allowed to be used to establish the correspondinglink, of the STA MLD.

It can be learned that this implementation helps the AP MLD notify theSTA MLD of the radio, allowed to be used to establish each link that theSTA MLD requests to establish, of the STA MLD. Further, if radio bitmapinformation of one link indicates that a radio, allowed to be used, ofthe STA MLD does not exist or is zero, it implicitly indicates that thelink fails to be established. If radio bitmap information of one linkindicates that there is one radio, allowed to be used, of the STA MLD,it implicitly indicates that the link is successfully established. Ifradio bitmap information of one link indicates that there are aplurality of radios, allowed to be used, of the STA MLD, it implicitlyindicates that the link is successfully established, and the pluralityof radios may all switch to the link.

Optionally, if radio bitmap information of a plurality of linksseparately indicates a same radio, allowed to be used, of the STA MLD,it implicitly indicates that the radio may be used to establish theplurality of links, and may perform link switching between the pluralityof links.

It can be learned that, in this implementation, whether linkestablishment succeeds is indicated, and the plurality of links mayfurther be established for the same radio, to help the radio performfast switching between the plurality of links, thereby avoiding aproblem of a relatively large delay caused due to switching performedafter a link is subsequently re-established.

Optionally, for related content of this implementation, refer to thecontent described in the first aspect and the second aspect. Details arenot described herein again.

According to a seventh aspect, this application provides a communicationapparatus. The apparatus may be a STA MLD, or may be an apparatus in theSTA MLD. The communication apparatus may alternatively be a processor ora chip system in the STA MLD. The communication apparatus may performthe method according to the first aspect. A function of thecommunication apparatus may be implemented by hardware, or may beimplemented by hardware by executing corresponding software. Thehardware or software includes one or more units corresponding to theforegoing function. The unit may be software and/or hardware. For anoperation performed by the communication apparatus and a beneficialeffect, refer to the method and the possible implementations in thefirst aspect, and the corresponding beneficial effect is achieved.Details are not described herein again. Alternatively, for an operationperformed by the communication apparatus and a beneficial effect, referto the method and the possible implementations in the third aspect, andthe corresponding beneficial effect is achieved. Details are notdescribed herein again. For an operation performed by the communicationapparatus and a beneficial effect, refer to the method and the possibleimplementations in the fifth aspect, and the corresponding beneficialeffect is achieved. Details are not described herein again.

According to an eighth aspect, this application provides a communicationapparatus. The apparatus may be an AP MLD, or may be an apparatus in theAP MLD. The communication apparatus may alternatively be a processor ora chip system in the AP MLD. The communication apparatus may perform themethod according to the second aspect. A function of the communicationapparatus may be implemented by hardware, or may be implemented byhardware by executing corresponding software. The hardware or softwareincludes one or more units corresponding to the foregoing function. Theunit may be software and/or hardware. For an operation performed by thecommunication apparatus and a beneficial effect, refer to the method andthe possible implementations in the second aspect, and the correspondingbeneficial effect is achieved. Repeated parts are not described again.Alternatively, for an operation performed by the communication apparatusand a beneficial effect, refer to the method and the possibleimplementations in the fourth aspect, and the corresponding beneficialeffect is achieved. Repeated parts are not described again.Alternatively, for an operation performed by the communication apparatusand a beneficial effect, refer to the method and the possibleimplementations in the sixth aspect, and the corresponding beneficialeffect is achieved. Repeated parts are not described again.

According to a ninth aspect, this application provides a communicationapparatus, where the communication apparatus may be a STA MLD or a chipsystem. The communication apparatus includes at least one processor, andwhen the processor invokes a computer program in a memory, the methodperformed by the STA MLD in any one of the first aspect or the possibleimplementations of the first aspect is performed, or the methodperformed by the STA MLD in any one of the third aspect or the possibleimplementations of the third aspect is performed, or the methodperformed by the STA MLD in any one of the fifth aspect or the possibleimplementations of the fifth aspect is performed.

According to a tenth aspect, this application provides a communicationapparatus, where the communication apparatus may be an AP MLD or a chipsystem. The communication apparatus includes at least one processor, andwhen the processor invokes a computer program in a memory, the methodperformed by the AP MLD in any one of the second aspect or the possibleimplementations of the second aspect is performed, or the methodperformed by the AP MLD in any one of the fourth aspect or the possibleimplementations of the fourth aspect is performed, or the methodperformed by the AP MLD in any one of the sixth aspect or the possibleimplementations of the sixth aspect is performed.

According to an eleventh aspect, this application provides acommunication apparatus, where the communication apparatus may be a STAMLD or a chip system. The communication apparatus includes a processorand a memory. The memory is configured to store a computer program; andthe processor is configured to execute the computer program stored inthe memory, to enable the communication apparatus to perform the methodperformed by the STA MLD in any one of the first aspect or the possibleimplementations of the first aspect, or the method performed by the STAMLD in any one of the third aspect or the possible implementations ofthe third aspect, or the method performed by the STA MLD in any one ofthe fifth aspect or the possible implementations of the fifth aspect.

According to a twelfth aspect, this application provides a communicationapparatus, where the communication apparatus may be an AP MLD or a chipsystem. The communication apparatus includes a processor and a memory.The memory is configured to store a computer program; and the processoris configured to execute the computer program stored in the memory, toenable the communication apparatus to perform the method performed bythe AP MLD in any one of the second aspect or the possibleimplementations of the second aspect, or the method performed by the APMLD in any one of the fourth aspect or the possible implementations ofthe fourth aspect, or the method performed by the AP MLD in any one ofthe sixth aspect or the possible implementations of the sixth aspect.

According to a thirteenth aspect, this application provides acommunication apparatus, where the communication apparatus may be a STAMLD. The communication apparatus includes a processor, a memory, and atransceiver. The transceiver is configured to receive a signal or send asignal; the memory is configured to store a computer program; and theprocessor is configured to invoke the computer program from the memory,to perform the method performed by the STA MLD in any one of the firstaspect or the possible implementations of the first aspect, or themethod performed by the STA MLD in any one of the third aspect or thepossible implementations of the third aspect, or the method performed bythe STA MLD in any one of the fifth aspect or the possibleimplementations of the fifth aspect.

According to a fourteenth aspect, this application provides acommunication apparatus, where the communication apparatus may be an APMLD. The communication apparatus includes a processor, a memory, and atransceiver. The transceiver is configured to receive a signal or send asignal; the memory is configured to store a computer program; and theprocessor is configured to invoke the computer program from the memory,to perform the method performed by the AP MLD in any one of the secondaspect or the possible implementations of the second aspect, or themethod performed by the AP MLD in any one of the fourth aspect or thepossible implementations of the fourth aspect, or the method performedby the AP MLD in any one of the sixth aspect or the possibleimplementations of the sixth aspect.

According to a fifteenth aspect, this application provides acommunication apparatus, where the communication apparatus may be a STAMLD or a chip system. The communication apparatus includes at least oneprocessor and a communication interface. The processor runs a computerprogram to perform the method performed by the STA MLD in any one of thefirst aspect or the possible implementations of the first aspect, or themethod performed by the STA MLD in any one of the third aspect or thepossible implementations of the third aspect, or the method performed bythe STA MLD in any one of the fifth aspect or the possibleimplementations of the fifth aspect.

According to a sixteenth aspect, this application provides acommunication apparatus, where the communication apparatus may be an APMLD or a chip system. The communication apparatus includes at least oneprocessor and a communication interface. The processor runs a computerprogram to perform the method performed by the AP MLD in any one of thesecond aspect or the possible implementations of the second aspect, orthe method performed by the AP MLD in any one of the fourth aspect orthe possible implementations of the fourth aspect, or the methodperformed by the AP MLD in any one of the sixth aspect or the possibleimplementations of the sixth aspect.

According to a seventeenth aspect, this application provides acomputer-readable storage medium. The computer-readable storage mediumis configured to store instructions, and when the instructions areexecuted, the method performed by the STA MLD in any one of the firstaspect or the possible implementations of the first aspect is performed,or the method performed by the STA MLD in any one of the third aspect orthe possible implementations of the third aspect is performed, or themethod performed by the STA MLD in any one of the fifth aspect or thepossible implementations of the fifth aspect is performed.

According to an eighteenth aspect, this application provides acomputer-readable storage medium. The computer-readable storage mediumis configured to store instructions, and when the instructions areexecuted, the method performed by the AP MLD in any one of the secondaspect or the possible implementations of the second aspect isperformed, or the method performed by the AP MLD in any one of thefourth aspect or the possible implementations of the fourth aspect isperformed, or the method performed by the AP MLD in any one of the sixthaspect or the possible implementations of the sixth aspect is performed.

According to a nineteenth aspect, this application provides a computerprogram product including instructions. When the instructions areexecuted, the method performed by the STA MLD in any one of the firstaspect or the possible implementations of the first aspect is performed,or the method performed by the STA MLD in any one of the third aspect orthe possible implementations of the third aspect is performed, or themethod performed by the STA MLD in any one of the fifth aspect or thepossible implementations of the fifth aspect is performed.

According to a twentieth aspect, this application provides a computerprogram product including instructions. When the instructions areexecuted, the method performed by the AP MLD in any one of the secondaspect or the possible implementations of the second aspect isperformed, or the method performed by the AP MLD in any one of thefourth aspect or the possible implementations of the fourth aspect isperformed, or the method performed by the AP MLD in any one of the sixthaspect or the possible implementations of the sixth aspect is performed.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram of a structure of a communication system100;

FIG. 2 is a schematic diagram of a structure of a communication system200;

FIG. 3 is a schematic diagram of a structure of a multi-link associationresponse frame;

FIG. 4 is a schematic flowchart of a multi-link establishment method 100according to an embodiment of this application;

FIG. 5 is another schematic diagram of a structure of a multi-linkassociation response frame according to an embodiment of thisapplication;

FIG. 6 is a schematic flowchart of a multi-link establishment method 200according to an embodiment of this application;

FIG. 7 is a schematic diagram of a structure of a multi-link elementaccording to an embodiment of this application;

FIG. 8 is a schematic flowchart of a multi-link establishment method 300according to an embodiment of this application;

FIG. 9 is still another schematic diagram of a structure of a multi-linkassociation response frame according to an embodiment of thisapplication;

FIG. 10 is still another schematic diagram of a structure of amulti-link association response frame according to an embodiment of thisapplication;

FIG. 11 is still another schematic diagram of a structure of amulti-link association response frame according to an embodiment of thisapplication;

FIG. 12 is still another schematic diagram of a structure of amulti-link association response frame according to an embodiment of thisapplication;

FIG. 13 is a schematic flowchart of a multi-link establishment method400 according to an embodiment of this application;

FIG. 14 is a schematic flowchart of a multi-link establishment method500 according to an embodiment of this application;

FIG. 15 is still another schematic diagram of a structure of amulti-link association response frame according to an embodiment of thisapplication;

FIG. 16 is still another schematic diagram of a structure of amulti-link association response frame according to an embodiment of thisapplication;

FIG. 17 is still another schematic diagram of a structure of amulti-link association response frame according to an embodiment of thisapplication;

FIG. 18 is still another schematic diagram of a structure of amulti-link association response frame according to an embodiment of thisapplication;

FIG. 19 is a schematic diagram of a structure of a communicationapparatus 100 according to an embodiment of this application;

FIG. 20 is a schematic diagram of a structure of a communicationapparatus 200 according to an embodiment of this application; and

FIG. 21 is a schematic diagram of a structure of a chip according to anembodiment of this application.

DESCRIPTION OF EMBODIMENTS

The following clearly and completely describes the technical solutionsin embodiments of this application with reference to the accompanyingdrawings in the embodiments of this application.

A wireless communication system applicable to the embodiments of thisapplication may be a wireless local area network (WLAN) or a cellularnetwork. A multi-link establishment method may be implemented by acommunication device in the wireless communication system or a chip or aprocessor in the communication device. The communication device may be awireless communication device that supports concurrent transmissionperformed on a plurality of links. For example, the communication deviceis referred to as a multi-link device or a multi-band device. Comparedwith a device that supports only single-link transmission, themulti-link device has higher transmission efficiency and a higherthroughput.

The embodiments of this application are mainly described by using anexample in which an IEEE 802.11 network, for example, a wireless localarea network (which is referred to as Wi-Fi 7 for short) of an 802.11series protocol such as 802.11be, is deployed. However, aspects of thisapplication may be extended to other networks that use various standardsor protocols, for example, Bluetooth, a high performance radio LAN(HIPERLAN) (a wireless standard that is similar to the IEEE 802.11standard and that is mainly used in Europe) and a wide area network(WAN), a wireless local area network (WLAN), a personal area network(PAN), or another now known or later developed network. Therefore, thevarious aspects provided in this application are applicable to anyappropriate wireless network regardless of coverage and a wirelessaccess protocol used.

As shown in FIG. 1 , using a wireless local area network as an example,a communication system 100 to which the embodiments of this applicationare applied includes a station 101 and a station 102. The station 101may communicate with the station 102 by using a plurality of links, toimprove a throughput. The station 101 may be a multi-link device, andthe station 102 may be a single-link device, a multi-link device, or thelike. In a scenario, the station 101 is an AP MLD, and the station 102is a STA MLD or a station (for example, a single-link station). Inanother scenario, the station 101 is a STA MLD, and the station 102 isan AP (for example, a single-link AP) or an AP MLD. In still anotherscenario, the station 101 is an AP MLD, and the station 102 is an AP MLDor an AP. In still another scenario, the station 101 is a STA MLD, andthe station 102 is a STA MLD or a STA (for example, a single-linkstation). Certainly, the wireless local area network may further includeanother device. A quantity and types of the devices shown in thecommunication system are merely an example.

For another example, FIG. 2 shows a communication system 200. In thecommunication system 200, an example of a scenario in which an AP MLDcommunicates with a STA MLD in a wireless local area network is used.The AP MLD includes an AP 1, an AP 2 and an AP 3 that are affiliated,the STA MLD includes a STA 1, a STA 2, and a STA 3 that are affiliated,and the AP MLD communicates with the STA MLD by using a link 1, a link2, and a link 3 in parallel.

To help understand the multi-link establishment method in thisapplication, related concepts in the embodiments of this application arebriefly described.

1. Multi-Link Device

The multi-link device includes one or more affiliated stations STAs(affiliated STAs). The affiliated STA is a logical station and can workon one link. The affiliated station may be an access point (AP) or anon-access point station (non-AP STA). For ease of description, in thisapplication, a multi-link device whose affiliated station is an AP maybe referred to as a multi-link AP, a multi-link AP device, or an APmulti-link device (AP MLD). A multi-link device whose affiliated stationis a non-AP STA may be referred to as a multi-link STA, a multi-link STAdevice, or a STA multi-link device (STA MLD). For ease of description,that “the multi-link device includes an affiliated STA” is also brieflydescribed as that “the multi-link device includes a STA” in theembodiments of this application.

The multi-link device may implement wireless communication according to802.11 family standards. For example, a station complying with anextremely high throughput (EHT), or a station complying with 802.11be orcompatible with a station supporting 802.11be implements communicationwith another device. Certainly, the another device may be a multi-linkdevice, or may not be a multi-link device.

For example, the multi-link device in the embodiments of thisapplication may be a single-antenna device, or may be a multi-antennadevice, for example, a device with more than two antennas. A quantity ofantennas included in the multi-link device is not limited in theembodiments of this application.

For example, the multi-link device is an apparatus having a wirelesscommunication function. The apparatus may be an integrated device, ormay be a chip, a processing system, or the like installed on theintegrated device. The device on which the chip or the processing systemis installed may be controlled by the chip or the processing system toimplement methods and functions in the embodiments of this application.For example, the STA MLD in the embodiments of this application has awireless transceiver function, may support the 802.11 series protocols,and may communicate with an AP MLD, another STA MLD, or a single-linkdevice. For example, the STA MLD is any user communication device thatallows a user to communicate with an AP and further communicate with aWLAN. For example, the STA MLD may be user equipment that can beconnected to a network, such as a tablet computer, a desktop computer, alaptop computer, a notebook computer, an ultra-mobile personal computer(UMPC), a handheld computer, a netbook, a personal digital assistant(PDA), or a mobile phone, may be an Internet of Things node in anInternet of Things, or may be a vehicle-mounted communication apparatusin an Internet of Vehicles. The STA MLD may alternatively be a chip anda processing system in the foregoing terminals.

The AP MLD in the embodiments of this application is an apparatus thatserves the STA MLD, and may support the 802.11 series protocols. Forexample, the AP MLD may be a communication entity such as acommunication server, a router, a switch, or a bridge, or the AP MLD mayinclude various forms of macro base stations, micro base stations, andrelay stations. Certainly, the AP MLD may alternatively be a chip and aprocessing system in the various forms of devices, to implement themethod and the function in the embodiments of this application. Inaddition, the multi-link device may support high-rate and low-latencytransmission. With the continuous evolution of application scenarios ofthe wireless local area network, the multi-link device may be furtherapplied to more scenarios. For example, the multi-link device may be asensor node (such as a smart water meter, a smart electricity meter, asmart air detection node) in a smart city, a smart device (such as asmart camera, a projector, a display, a TV, a stereo, a refrigerator,and a washing machine) in smart home, a node in the internet of things,an entertainment terminal (for example, a wearable device such as an ARand a VR), a smart device (such as a printer and a projector) in smartoffice, an IoV device in the internet of vehicles, and someinfrastructures (such as a vending machine, a self-service navigationstation in a supermarket, self-service cash register device, and aself-service ordering machine) in daily life scenarios. Specific formsof the STA MLD and the AP MLD are not specifically limited in theembodiments of this application, and are merely examples for descriptionherein. The 802.11 protocol may be a protocol that supports 802.11be oris compatible with 802.11be.

A frequency band on which the multi-link device operates may include butis not limited to sub 1 GHz, 2.4 GHz, 5 GHz, 6 GHz, and high frequency60 GHz.

2. Multi-Link Establishment Operation

As shown in FIG. 2 , the STA MLD performs the multi-link establishmentoperation, to establish the plurality of links, for example, the link 1,the link 2, and the link 3, to the AP MLD. The multi-link establishmentoperation may also be referred to as a multi-link association operation.To be specific, the STA MLD may be associated with the plurality oflinks to the AP MLD by using the multi-link establishment operation. Forexample, as shown in FIG. 2 , the STA 1 of the STA MLD is associatedwith the link 1, the STA 2 is associated with the link 2, and the STA 3is associated with the link 3. The multi-link establishment operationmay also be referred to as a multi-link device association operation. Tobe specific, the STA MLD may associate each STA in the STA MLD with theAP in the AP MLD by using the multi-link establishment operation. Forexample, as shown in FIG. 2 , the STA 1 is associated with the AP 1, theSTA 2 is associated with the AP 2, and the STA 3 is associated with theAP 3.

In the multi-link establishment operation, the STA MLD establishes theplurality of links to the AP MLD by exchanging a multi-link associationrequest frame and a a multi-link association response frame on a link.The link is referred to as a sending link or a transmitted link, andanother link is referred to as a non-sending link or a non-transmittedlink.

Using the communication system shown in FIG. 2 as an example, themulti-link establishment operation may include the following steps.

The STA MLD sends the multi-link association request frame to the AP MLDon the link 1. The multi-link association request frame carries not onlystation-side information of the link 1, but also station-sideinformation of the link 2 and the link 3. The station-side informationincludes a station identifier corresponding to the link, and the like.The link 1 is a transmitted link, and the link 2 and the link 3 arenon-transmitted links.

The AP MLD returns the multi-link association response frame to the STAMLD. The multi-link association response frame carries not only thestation-side information of the link 1, but also access point-sideinformation of the link 1, the station-side information and accesspoint-side information of the link 2, and the station-side informationand access point-side information of the link 3. In this way, amulti-link connection is established between the STA MLD and the AP MLD.

The multi-link association request frame in this application is anassociation request frame that carries a multi-link element. Optionally,the multi-link association request frame may also be referred to as amulti-link establishment request frame, an association request frame, oran establishment request frame. The multi-link association responseframe in this application is an association response frame that carriesa multi-link element. Optionally, the multi-link association responseframe may also be referred to as a multi-link establishment responseframe, an association response frame, or an establishment responseframe. The following describes the multi-link association response framewith reference to FIG. 3 .

3. Multi-Link Association Response Frame

Station-side information and access point-side information carried inthe multi-link association response frame may be located in a multi-linkelement. Both the multi-link association request frame and themulti-link association response frame carry the multi-link element. Asshown in FIG. 3 , information carried in the multi-link element in themulti-link association response frame and carried in the multi-linkassociation response frame is divided into two parts. One part ismulti-link device information (MLD-level info), and the other part islink configuration information of each link (per link profile info).Link configuration information of each non-transmitted link may bereferred to as non-transmitted link configuration information for short.Certainly, the multi-link element may further include another field orother information.

Content of the link configuration information in the multi-linkassociation request frame is different from content of the linkconfiguration information in the multi-link association response frame.For example, both the link configuration information in the multi-linkassociation request frame and the link configuration information in themulti-link association response frame carry a link identifier of a link,radio-related information, and the like. However, the link configurationinformation in the multi-link association response frame may not carryrelated information of a station side. Specifically, this is not limitedin the embodiments of this application.

The MLD-level info carries related information of the multi-link device,for example, a service access point media access control address (SAPMAC address) of the STA MLD and a service access point media accesscontrol address of the AP MLD. The per link profile info starts with afixed element, namely, a link-index element. The link-index elementcarries a link identifier (link ID) of a corresponding link, to indicatethe link of which the link profile info is related information. Thelink-index element further carries an element, which is denoted as an xelement in FIG. 3 , of a STA side (or an AP side) of the link. The xelement is an element having content different from that of an elementof a STA side (or an AP side) of the transmitted link. The STA MLD mayobtain information such as a link ID of each link of the AP MLD byreceiving a probe response frame or a beacon frame.

In addition, aside from carrying the multi-link element, the multi-linkassociation response frame may further carry other fields. As shown inTable 1, based on sequence numbers, the other fields are: a capabilityinformation field, a status code field, an association identifier (AID)field, a supported rate and a basic service set (BSS) field, and thelike. An association response frame is sent by an access point in anassociation process between single-link devices, and the multi-linkassociation response frame is sent by an access point multi-link devicein an association process between multi-link devices.

TABLE 1 Association response frame Sequence number Information Comment 1Capability information 2 Status code 3 Association identifier (AID) 4Supported rate and BSS If dot11DMGOptionImplemented member selector istrue, this element is not present . . . . . . . . .

The status code field is used to indicate whether the multi-linkestablishment operation succeeds, whether the multi-link deviceassociation operation succeeds, or whether each STA in the STA MLD isassociated with each AP in the AP MLD. Table 2 shows status code.

TABLE 2 Status code field Status code Name Meaning 0 Succeed Succeed 1Rejected, and rejected for an Failure for an unspecified unspecifiedreason reason 2 Tunneled direct link setup (tunneled Direct linkscheduling is direct link setup, TDLS) is rejected, rejected, butalternative and an alternative option is provided scheduling is provided. . . . . . . . .

4. Radio of a Multi-Link Device

A multi-link device may be a single-antenna (or single-radio module orsingle-radio) multi-link device, or may be a multi-antenna (ormulti-radio module or multi-radio) multi-link device. A quantity ofantennas included in the multi-link device is not limited in theembodiments of this application. In other words, the multi-link devicemay include one or more radios, where each radio may support one or moreforegoing described frequency bands. It should be noted that the radioin this solution includes not only a radio module, but also a basebandprocessing module. Optionally, in this application, a radio of a STA MLDmay also be referred to as a station of the STA MLD.

When one radio of the STA MLD may support a plurality of frequencybands, the radio may switch between links, separately corresponding tothe plurality of frequency bands, of an AP MLD. For example, as shown inFIG. 2 , one radio of the STA MLD may support two frequency bands,namely, 5 GHz and 6 GHz. Therefore, the radio may switch between thelink 2 and the link 3. In other words, the STA 2 corresponding to thelink 2 and the STA 3 corresponding to the link 3 may share one radio.That is, the radio may be used to virtualize the two STAs. In otherwords, the link 2 and the link 3 may share one radio, or the STA 2 andthe STA 3 may share one radio.

Although the STA MLD may establish the two links by using the radio,because the two links share one radio of the STA MLD, only one of thetwo links can be in an enable state, and the other link is in a disablestate at a same time. Optionally, because the STA MLD has establishedthe link 2 and the link 3 by using the radio, the STA MLD may quicklyswitch from the link 2 to the link 3, so that the link 2 changes fromthe enable state to the disable state, and the link 3 changes from thedisable state to the enable state.

It should be noted that all links discussed in this application arelinks requested, by using the multi-link association request frame, tobe established. All radios of the STA MLD discussed in this applicationare radios whose radio-related information is carried in the multi-linkassociation request frame. A quantity of APs of the AP MLD discussed inthis application may be a quantity of independent radios of the AP MLD.In addition, all the APs of the AP MLD discussed in this application areAPs corresponding to link identifiers carried in the multi-linkassociation request frame.

This application further provides a multi-link establishment method 100and a multi-link establishment method 200. In both the multi-linkestablishment method 100 and the multi-link establishment method 200,radio bitmap information may be used to learn of a radio allowed to beused to establish each link. Further, this helps determine, when thereis no radio allowed to be used for the link, that the link fails to beestablished; or determine, when there is the radio allowed to be usedfor the link, that the link is successfully established. When a sameradio is allowed to be used to establish a plurality of links, the radiocan perform fast link switching between the plurality of links, therebyavoiding a problem of a relatively long delay caused by reestablishingthe link, and improving multi-link establishment flexibility.

This application further provides a multi-link establishment method 300.The multi-link establishment method 300 may indicate whether each linkthat a STA MLD requests to establish is successfully established.Different from the manner in which only one status code field in theassociation response frame is used to indicate whether STA associationis successful, the multi-link establishment method 300 is applicable toa multi-link device. Link establishment status information may be usedto indicate whether each link that the STA MLD requests to establish issuccessfully established, that is, a link that fails to be establishedis allowed to exist, thereby improving multi-link establishmentflexibility.

This application provides a multi-link establishment method 400. In themulti-link establishment method 400, in a reassociation process, apredefined rule is used to enable a STA MLD to reserve a part ofparameters in previously associated configuration information, therebyreducing signaling overheads.

This application further provides a multi-link establishment method 500.In the multi-link establishment method 500, in a reassociation process,a STA MLD is explicitly indicated, by using reassociation information,to reserve a part of parameters in previously associated configurationinformation, thereby reducing signaling overheads. It can be learnedthat, compared with a current manner in which when a single-link deviceneeds to modify capability information or some attributes of thesingle-link device, the single-link device deletes previously associatedconfiguration information and obtains configuration information again ina reassociation operation process, the multi-link establishment method400 and the multi-link establishment method 500 help reduce signalingoverheads.

In addition, the multi-link establishment method 100 to the multi-linkestablishment method 300 need to resolve a same problem, have specifictechnical features with a same function, and achieve similar beneficialeffects. Therefore, the multi-link establishment method 100 to themulti-link establishment method 300 belong to a same inventive concept,and satisfy a unity requirement.

The multi-link association response frame may carry one or more of thereassociation information, the link establishment status information,and the radio bitmap information. This is not limited in the embodimentsof this application.

The following separately describes this application with reference tothe accompanying drawings.

Embodiment 1

This application further provides the multi-link establishment method100. In the multi-link establishment method 100, a radio, allowed to beused to establish each link in a plurality of links that a STA MLDrequests to establish, of the STA MLD may be indicated.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, an AP MLD has an AP 1, an AP 2, and an AP 3, andlinks of the AP MLD are separately a link 1, a link 2, and a link 3. Inthe multi-link establishment method 100, for the link 1, the link 2, andthe link 3 that the STA MLD requests to establish, a radio that isallowed to be used to establish the link 1 and that is of the STA MLD, aradio that is allowed to be used to establish the link 2 and that is ofthe STA MLD, and a radio that is allowed to be used to establish thelink 3 and that is of the STA MLD may be indicated.

Alternatively, it may be described as one or more of the following: Inthe multi-link establishment method 100, an AP that each radio of theSTA MLD is allowed to be associated with and that is in the AP MLD maybe indicated; or a link that is allowed to share each radio of the STAMLD in the plurality of links that the STA MLD requests to establish maybe indicated; or a link that each radio of the STA MLD is allowed to beused to establish may be indicated; or a radio that each AP in the APMLD is allowed to be associated with and that is of the STA MLD may beindicated.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, an AP MLD has an AP 1, an AP 2, and an AP 3, andlinks of the AP MLD are separately a link 1, a link 2, and a link 3. Inthe multi-link establishment method 100, APs that the radio 1 and theradio 2 are separately allowed to be associated with and that are in theAP MLD may be indicated; or a link that is allowed to share the radio 1and a link that is allowed to share the radio 2 in the link 1, the link2, and the link 3 may be indicated; or a link that the radio 1 isallowed to be used to establish and a link that the radio 2 is allowedto be used to establish may be indicated; or a radio that the AP 1 isallowed to be associated with, a radio that the AP 2 is allowed to beassociated with, and a radio that the AP 3 is allowed to be associatedwith may be indicated.

FIG. 4 is a schematic flowchart of the multi-link establishment method100 according to an embodiment of this application. The multi-linkestablishment method 100 includes but is not limited to the followingsteps.

S101: The STA MLD sends a multi-link association request frame.

S102: The AP MLD receives the multi-link association request frame.

S103: The AP MLD sends a multi-link association response frame, wherethe multi-link association response frame includes radio bitmapinformation, and the radio bitmap information is used to indicate aradio, allowed to be used to establish each link in links that the STAMLD requests to establish, of the STA MLD.

S104: The STA MLD receives the multi-link association response frame.

Further, the multi-link establishment method 100 may further include:The STA MLD determines, based on the radio bitmap information, aplurality of links that are allowed to use a same radio, to perform linkswitching between the plurality of links by using the radio; the STA MLDdetermines, based on the radio bitmap information, a link that has noradio allowed to be used, to determine that the link fails to beestablished; and the STA MLD determines, based on the radio bitmapinformation, a link that has a radio allowed to be used to establish thelink, to determine that the link is successfully established.

It can be learned that, in this embodiment of this application, the APMLD is enabled to not only notify the STA MLD of the radio, allowed tobe used to establish each link that the STA MLD requests to establish,of the STA MLD. In this way, the STA MLD determine, based on the radiobitmap information, whether a link is successfully established. In otherwords, the AP MLD is allowed to reject establishing a part of the linksrequested by the STA MLD, thereby improving multi-link establishmentflexibility. In addition, the STA MLD determines, based on the radiobitmap information, the plurality of links that may be established byusing the same radio, to help the radio flexibly switch between theplurality of links. In other words, a quantity of radios of the STA MLDis allowed to be less than a quantity of links that the STA MLD requeststo establish, thereby further improving the multi-link establishmentflexibility.

In an implementation, the multi-link association request frame carriesradio quantity information, where the radio quantity information is usedto indicate the quantity of radios of the STA MLD. A quantity of bitsoccupies by the radio quantity information is determined based on thequantity of radios of the STA MLD. For example, assuming that thequantity of radios of the STA MLD is two, the quantity of bits occupiesby the radio quantity information is one. Assuming that the quantity ofradios of the STA MLD is four, the quantity of bits occupies by theradio quantity information is two.

In another implementation, the quantity of radios of the STA MLD isdetermined based on radio-related information carried in the multi-linkassociation request frame. For example, a quantity of radio media accesscontrol addresses carried in the multi-link association request frame isthe quantity of radios of the STA MLD.

A total quantity of bits occupied by the radio bitmap information=aproduct of the quantity of radios of the STA MLD and a quantity of APsof the AP MLD. Alternatively, a total quantity of bits occupied by theradio bitmap information=a product of the quantity of radios of the STAMLD and a quantity of links that the STA MLD requests to establish. Itcan be learned that the radio quantity information carried in themulti-link association request frame helps determine the quantity ofbits of the radio bitmap information or a length of the radio bitmapinformation.

Specifically, the radio bitmap information is used to indicate theradio, allowed to be used to establish each link in the plurality oflinks that the STA MLD requests to establish, of the STA MLD. One linkcorresponds to R bits in the radio bitmap information, where R is thequantity of radios of the STA MLD. One of the R bits corresponds to oneradio of the STA MLD, and the bit indicates whether the correspondingradio is allowed to be used to establish the link. In addition, the Rbits, corresponding to each link, in the radio bitmap information may bedetermined based on a link identifier or predefined. The bit,corresponding to each radio, in the R bits may be determined based on asequence of the related information of the radios carried in themulti-link association request frame, or predefined. For example, thequantity R of radios of the STA MLD is equal to two, and a sequence inwhich the radio-related information carried in the multi-linkassociation request frame sent by the STA MLD appears is that relatedinformation of the radio 2 appears first, and related information of theradio 1 appears next. In this case, the 1^(st) bit in the two bitscorresponds to the radio 2, and the 2^(nd) bit corresponds to the radio1.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, and links that the STA MLD requests to establishare a link 1, a link 2, and a link 3. In this case, the radio bitmapinformation comprises six bits, and R is equal to two. Two bitscorresponding to the link 1, two bits corresponding to the link 2, andtwo bits corresponding to the link 3 in the six bits may be: the link 1corresponds to the first two bits, the link 2 corresponds to the middletwo bits, and the link 3 corresponds to the last two bits. Bits,separately corresponding to the two radios, in every two bits may be:the 1^(st) bit corresponds to the radio 1, and the 2^(nd) bitcorresponds to the radio 2. If the radio bitmap information is 100101,it indicates that a radio allowed to be used to establish the link 1 isthe radio 1, and a radio allowed to be used to establish the link 2 anda radio allowed to be used to establish the link 3 are both the radio 2.It can be learned that the link 1, the link 2, and the link 3 are allsuccessfully established, and the radio 2 may be used to establish thelink 2 and the link 3. Therefore, the radio 2 may switch between thelink 2 and the link 3.

In addition, the radio bitmap information may be carried not only in themulti-link association response frame, but also in the multi-linkassociation request frame. The multi-link association request framecarrying the radio bitmap information may notify the AP MLD of theforegoing correspondences requested by the STA MLD. An example in whichthe radio bitmap information is in the multi-link association responseframe is used for description below.

The radio bitmap information may be carried in MLD-level info in amulti-link element, to indicate a correspondence between each radio ofthe STA MLD and each AP in the AP MLD, or a correspondence between eachradio of the STA MLD and each link that the STA MLD requests toestablish. The radio bitmap information may be referred to as a radio'sbitmap indication for each link (Radio's Bitmap indication for eachlink) field. As shown in FIG. 5 , the radio's bitmap indication for eachlink field is located in the MLD-level info in the multi-link element.

Optionally, the radio bitmap information is described from differentperspectives, and the radio bitmap information corresponds to differentdescriptions. For example, the radio bitmap information is used toindicate a radio that each AP in the AP MLD is allowed to be associatedwith and that is of the STA MLD. Alternatively, the radio bitmapinformation is used to indicate an AP that each radio of the STA MLD isallowed to be associated with and that is of the AP MLD. Alternatively,the radio bitmap information is used to indicate a link that is allowedto share each radio of the STA MLD in a plurality of links that the STAMLD requests to establish. Alternatively, the radio bitmap informationis used to indicate a link that each radio of the STA MLD is allowed tobe used to establish. In other words, the radio bitmap information mayindicate the correspondence between each radio of the STA MLD and eachAP in the AP MLD, or the correspondence between each radio of the STAMLD and each link that the STA MLD requests to establish.

How another description manner of the radio bitmap informationspecifically indicates the correspondences when the radio bitmapinformation is located in the MLD-level info in the multi-link elementis described below.

In a description, the radio bitmap information is used to indicate aradio of the STA MLD, where the radio is allowed to be used to establisheach link of the AP MLD with an AP of the link. One link corresponds toR bits in the radio bitmap information, where R is the quantity ofradios of the STA MLD. One bit in the R bits corresponds to one radio ofthe STA MLD, and indicates whether the corresponding radio is allowed tobe used to establish the link with the AP. In addition, the R bits,corresponding to each link, in the radio bitmap information may bedetermined based on a link identifier or predefined. The bits,separately corresponding to the R radios, in the R bits may bedetermined based on a sequence of the related information of the radioscarried in the multi-link association request frame, or predefined.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, and links that the STA MLD requests to establishare a link 1, a link 2, and a link 3. In this case, the radio bitmapinformation is six bits, and R is equal to two. The radio bitmapinformation indicates a radio that may be used to establish the link 1with an AP 1, a radio that may be used to establish the link 2 with anAP 2, and a radio that may be used to establish the link 3 with an AP 3in the radio 1 and the radio 2. Two bits corresponding to the link 1,two bits corresponding to the link 2, and two bits corresponding to thelink 3 in the six bits may be: the link 1 corresponds to the first twobits, the link 2 corresponds to the middle two bits, and the link 3corresponds to the last two bits. Bits, separately corresponding to thetwo radios, in every two bits may be: the 1^(st) bit corresponds to theradio 1, and the 2^(nd) bit corresponds to the radio 2. If the radiobitmap information is 100101, it indicates that the radio 1 is allowedto be used to establish the link 1 with the AP 1, and the radio 2 is notallowed to be used to establish the link 1 with the AP 1; the radio 1 isnot allowed to be used to establish the link 2 with the AP 2, and theradio 2 is allowed to be used to establish the link 2 with the AP 2; andthe radio 1 is not allowed to be used to establish the link 3 with theAP 3, and the radio 2 is allowed to be used to establish the link 3 withthe AP 3. It can be learned that the link 1, the link 2, and the link 3are all successfully established. In addition, the radio 2 may establishthe link 2 with the AP 2, and establish the link 3 with the AP 3.Therefore, the radio 2 may switch between the link 2 and the link 3respectively.

In another description, the radio bitmap information is used to indicatethe radio that each AP in the AP MLD is allowed to be associated withand that is of the STA MLD. One AP corresponds to R bits in the radiobitmap information, where R is the quantity of radios of the STA MLD.One bit in the R bits corresponds to one radio of the STA MLD, andindicates whether the corresponding radio is allowed to be associatedwith the AP. In addition, the R bits, corresponding to each AP, in theradio bitmap information may be determined based on an associationidentifier of the AP or predefined. The bits, separately correspondingto the R radios, in the R bits may be determined based on a sequence ofthe related information of the radios carried in the multi-linkassociation request frame, or predefined.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, and the AP MLD has three APs, namely, an AP 1, anAP 2, and an AP 3. In this case, the radio bitmap information is sixbits, and R is equal to two. Two bits corresponding to the AP 1, twobits corresponding to the AP 2, and two bits corresponding to the AP 3in the six bits may be: the AP 1 corresponds to the first two bits, theAP 2 corresponds to the middle two bits, and the AP 3 corresponds to thelast two bits. Bits, separately corresponding to the two radios, inevery two bits may be: the 1^(st) bit corresponds to the radio 1, andthe 2^(nd) bit corresponds to the radio 2. If the radio bitmapinformation is 100101, it indicates that a radio that the AP 1 isallowed to be associated with is the radio 1, and a radio that the AP 2is allowed to be associated with and a radio that the AP 3 is allowed tobe associated with are both the radio 2. It can be learned that theradio 2 switches between the AP 2 and the AP 3.

In still another description, the radio bitmap information is used toindicate the AP that each radio of the STA MLD is allowed to beassociated with and that is of the AP MLD. One radio corresponds to Sbits in the radio bitmap information, where S is the quantity of APs ofthe AP MLD. One bit in the S bits corresponds to one AP of the AP MLD,and indicates whether the radio is allowed to be associated with the AP.In addition, the S bits, corresponding to each radio, in the radiobitmap information may be determined based on a sequence of the relatedinformation of the radios carried in the multi-link association requestframe, or predefined. The bits, separately corresponding to the S APs,in the S bits may be determined based on association identifiers of theAPs or predefined.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, and the AP MLD has three APs, namely, an AP 1, anAP 2, and an AP 3. In this case, the radio bitmap information is sixbits, and S is equal to two. Three bits corresponding to the radio 1 andthree bits corresponding to the radio 2 in the six bits may be: theradio 1 corresponds to the first three bits, and the radio 2 correspondsto the last three bits. Bits, separately corresponding to the three APs,in every three bits may be: the 1^(st) bit corresponds to the AP 1, the2^(nd) bit corresponds to the AP 2, and the 3^(rd) bit corresponds tothe AP 3. If the radio bitmap information is 010101, it indicates thatthe radio 1 is allowed to be associated with the AP 2, and the radio 2is allowed to be associated with the AP 1 and the AP 3. It can belearned that the radio 2 switches between the AP 1 and the AP 3.

In still another description, the radio bitmap information is used toindicate the link that is allowed to share each radio of the STA MLD inthe plurality of links that the STA MLD requests to establish. One radiocorresponds to S bits in the radio bitmap information, where S is thequantity of links of the AP MLD. One bit in the S bits corresponds toone link of the STA MLD, and indicates whether the corresponding link isallowed to share the radio. In addition, the S bits, corresponding toeach radio, in the radio bitmap information may be determined based on asequence of the related information of the radios carried in themulti-link association request frame, or predefined. The bits,separately corresponding to the S links, in the S bits may be determinedbased on a link identifier or predefined.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, and links that the STA MLD requests to establishare a link 1, a link 2, and a link 3. In this case, the radio bitmapinformation is six bits, and S is equal to three. Three bitscorresponding to the radio 1 and three bits corresponding to the radio 2in the six bits may be: the radio 1 corresponds to the first three bits,and the radio 2 corresponds to the last three bits. Bits, separatelycorresponding to the link 1, the link 2, and the link 3, in every threebits may be: the 1^(st) bit corresponds to the link 1, the 2^(nd) bitcorresponds to the link 2, and the 3^(rd) bit corresponds to the link 3.If the radio bitmap information is 010101, it indicates that a link thatis allowed to share the radio 1 is the link 2, and a link that isallowed to share the radio 2 is the link 1 and the link 3. It can belearned that the radio 2 switches between the link 1 and the link 3.

In still another description, the radio bitmap information is used toindicate the link that each radio of the STA MLD is allowed to be usedto establish. One radio corresponds to S bits in the radio bitmapinformation, where S is the quantity of links of the AP MLD. One bit inthe S bits corresponds to one link of the STA MLD, and indicates whetherthe radio is allowed to be used to establish the corresponding link. Inaddition, the S bits, corresponding to each radio, in the radio bitmapinformation may be determined based on a sequence of the relatedinformation of the radios carried in the multi-link association requestframe, or predefined. The bits, separately corresponding to the S links,in the S bits may be determined based on a link identifier orpredefined.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, and links that the STA MLD requests to establishare a link 1, a link 2, and a link 3. In this case, the radio bitmapinformation is six bits, and S is equal to three. Three bitscorresponding to the radio 1 and three bits corresponding to the radio 2in the six bits may be: the radio 1 corresponds to the first three bits,and the radio 2 corresponds to the last three bits. Bits, separatelycorresponding to the link 1, the link 2, and the link 3, in every threebits may be: the 1^(st) bit corresponds to the link 1, the 2^(nd) bitcorresponds to the link 2, and the 3^(rd) bit corresponds to the link 3.If the radio bitmap information is 010101, it indicates that a link thatthe radio 1 is allowed to be used to establish is the link 2, and a linkthat the radio 2 is allowed to be used to establish is the link 1 andthe link 3. It can be learned that the radio 2 switches between the link1 and the link 3.

It can be learned that, in this embodiment of this application, when theradio bitmap information is interpreted from different perspectives,each bit in the radio bitmap information corresponds to differentmeanings. Specifically, one of the interpretations, namely, one of thedescriptions, is determined in a manner of predefining or signalingconfiguration. This is not specifically limited in this embodiment ofthis application. In conclusion, regardless of how the radio bitmapinformation is described, the STA MLD may learn of information such asthe radio that is allowed by the AP MLD to be used on a STA side of alink, whether a link is successfully established, and the links betweenwhich the radio may quickly switch. As a result, multi-linkestablishment flexibility is greatly improved.

Embodiment 2

This application further provides the multi-link establishment method200. As shown in FIG. 6 , the multi-link establishment method 200 issimilar to the multi-link establishment method 100. For example, stepS201 in FIG. 6 is the same as step S101 in FIGS. 4 , and S202 is thesame as S102 in FIG. 4 . An only difference is that in the multi-linkestablishment method 200, a multi-link association response frame inS203 and S204 carries a plurality of pieces of radio bitmap information.One piece of radio bitmap information corresponds to one link that theSTA MLD requests to establish, and the radio bitmap information is usedto indicate a radio allowed to be used to establish the correspondinglink.

Radio bitmap information of a transmitted link is located in MLD-levelinfo in a multi-link element. Radio bitmap information of anon-transmitted link is located in Per-link profile info in themulti-link element. In other words, the radio bitmap information in theMLD-level info in the multi-link element is used to indicate acorrespondence between the transmitted link and each radio of the STAMLD. The radio bitmap information in the Per-link profile info in themulti-link element is used to indicate a correspondence between thecorresponding non-transmitted link and each radio of the STA MLD.

The radio frequency bitmap information may be referred to as a bitmapcorresponding to non-AP MLD's radios field, or a bitmap corresponding toSTA MLD's radios. For example, as shown in FIG. 7 , it is assumed that alink 1 is a transmitted link, and a link 2 and a link 3 arenon-transmitted links. In this case, as shown in FIG. 7 , a bitmapcorresponding to STA MLD's radios of the link 1 is located in MLD-levelinfo in a multi-link element, and a bitmap corresponding to STA MLD'sradios of the link 2 and a bitmap corresponding to STA MLD's radios ofthe link 3 are separately located in Per-link profile info in themulti-link element. Using the link 2 as an example, as shown in FIG. 7 ,the bitmap corresponding to STA MLD's radios of the link 2 is located ina link-index element of non-transmitted link 2 profile info in themulti-link element. In addition, the link-index element may furthercarry an element identifier (element ID), a length, a link identifier(link ID), and an enable/disable indication. The “enable/disableindication” may be translated as an “enable/disable indication”.

A quantity of bits occupied by the radio bitmap information of thetransmitted link and a quantity of bits occupied by the radio bitmapinformation of the non-transmitted link are both equal to the quantityof radios of the STA MLD. The radio quantity information carried in themulti-link association request frame helps determine the quantity ofbits of the radio bitmap information or a length of the radio bitmapinformation.

Similarly, radio bitmap information of one link may also correspond todifferent description manners from another perspective. For example,radio bitmap information of one link is used to indicate a radio allowedto be used to establish the link, or used to indicate a radio, allowedto be used to establish the link, of the STA MLD. Radio bitmapinformation of each link is R bits, where R is the quantity of radios ofthe STA MLD. One of the R bits corresponds to one radio of the STA MLD,and indicates whether the corresponding radio is allowed to be used toestablish the link. In addition, the bit, corresponding to each radio,in the radio bitmap information may be determined based on a sequence ofthe related information of the radios carried in the multi-linkassociation request frame, or predefined.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, and links that the STA MLD requests to establishare a link 1, a link 2, and a link 3. In this case, the radio bitmapinformation of each link is two bits. Bits, separately corresponding tothe two radios, in every two bits may be: the 1^(st) bit corresponds tothe radio 1, and the 2^(nd) bit corresponds to the radio 2. If radiobitmap information of the link 1 is 10, it indicates that a radioallowed to be used to establish the link 1 is the radio 1. If radiobitmap information of the link 2 is 10, it indicates that a radioallowed to be used to establish the link 2 is the radio 1. If radiobitmap information of the link 3 is 01, it indicates that a radioallowed to be used to establish the link 3 is the radio 2. It can belearned that the STA MLD may switch between the link 1 and the link 2 byusing the radio 1.

Similar to the foregoing multi-link establishment method 100, in themulti-link establishment method 200, information such as whether a linkis successfully established and links between which a radio may quicklyswitch may be learned, thereby greatly improving multi-linkestablishment flexibility. Specifically, when it is assumed that a valueof one bit in the radio bitmap information of a link is zero, itindicates that a radio corresponding to the bit cannot establish thelink. When a value of one bit in the radio bitmap information a link isone, it indicates that a radio corresponding to the bit is allowed to beused to establish the link. In this case, the quantity of radios of theSTA MLD is R. If radio frequency bitmap information of a link is Rzeros, it indicates that the link cannot be successfully established byusing any radio of the STA MLD, that is, it implicitly indicates thatthe link fails to be established. If a plurality of bits in radio bitmapinformation of a link is one, it indicates that the link may besuccessfully established by using a plurality of radios of the STA MLD,where the plurality of radios are radios separately corresponding to theplurality of bits.

For example, it is assumed that the STA MLD has two radios, namely, aradio 1 and a radio 2, and radio bitmap information of one link is twobits. The 1^(st) bit corresponds to the radio 1, and the 2^(nd) bitcorresponds to the radio 2. If the radio bitmap information of the linkis 10, it indicates that the link may be established by using the radio1. If the radio bitmap information of the link is 01, it indicates thatthe link may be established by using the radio 2. If the radio bitmapinformation of the link is 11, it indicates that the link may beestablished by using both the radio 1 and the radio 2. If the radiobitmap information of the link is 00, it indicates that the link cannotbe established by using the radio 1 or the radio 2. Therefore, it mayimplicitly indicate that the link fails to be established.

It can be learned that, in the multi-link establishment method 100 andthe multi-link establishment method 200, a radio supporting a pluralityof frequency bands in the STA MLD may request to establish a pluralityof links to the AP MLD, where the plurality of links share the radio.Because one radio of the STA MLD may communicate with the AP MLD on onlyone link at any time, after a plurality of links sharing the radio aresuccessfully established, one of the links may be set to an enablestatus, and the others are set to a disable status. If the STA MLDswitches from the link to another link, the link is switched from theenable status to the disable status, and a time-consuming linkestablishment operation does not need to be re-initiated. In otherwords, in this embodiment of this application, the radio supporting theplurality of frequency bands in the STA MLD switches between theplurality of links of the AP MLD, and the time-consuming linkestablishment operation does not need to be re-initiated.

In addition, in the multi-link establishment method 100 and themulti-link establishment method 200, for a case in which a same radioestablishes a plurality of links, the multi-link association responseframe further needs to carry other information, to notify the STA MLD ofa link that is initially in the enable status and a link that is in thedisable status. For example, link configuration information of each linkin the multi-link association response frame may carry a statusindication, to indicate whether the link is in the enable status or thedisable status.

In addition, for a case in which a same link is allowed to beestablished by a plurality of radios, the multi-link associationresponse frame further needs to carry other information, to notify theSTA MLD of a radio initially allowed to be used to establish the link.For example, link configuration information of each link in themulti-link association response frame may carry an index of a MACaddress of a radio, to notify the STA MLD of a radio initiallyestablishing the link.

In addition, in the multi-link establishment method 100 and themulti-link establishment method 200, the radio bitmap information may becarried not only in the multi-link association response frame of the1^(st) association between the STA MLD and the AP MLD, but also in areassociation response frame of a reassociation between the STA MLD andthe AP MLD.

Embodiment 3

This application further provides the multi-link establishment method300. The multi-link establishment method 300 may indicate whether eachlink that the STA MLD requests to establish is successfully established.In other words, different from that a status code field in a requestresponse frame indicates only whether the STA MLD is successfullyassociated with the AP MLD, in the multi-link establishment method 300,whether each link that the STA MLD requests to establish is successfullyestablished may be indicated. As shown in FIG. 8 , the multi-linkestablishment method 300 includes but is not limited to the followingsteps.

S301: The STA MLD sends a multi-link association request frame.

S302: The AP MLD receives the multi-link association request frame.

S303: The AP MLD sends a multi-link association response frame, wherethe multi-link association response frame includes link establishmentstatus information, and the link establishment status information isused to indicate a link establishment status of each link that the STAMLD requests to establish.

S304: The STA MLD receives the multi-link association response frame.

Optionally, the multi-link association request frame and the multi-linkassociation response frame in steps S301 to S304 may be a multi-linkassociation request frame and a multi-link association response frame inthe initial association process between the STA MLD and the AP MLD, ormay be a reassociation request frame and a reassociation response framein a reassociation process between the STA MLD and the AP MLD. In otherwords, the reassociation response frame may also carry the linkestablishment status information.

In the multi-link establishment method 300, the link establishmentstatus information may include but is not limited to the following fouroptional implementations, to indicate the link establishment status ofeach link that the STA MLD requests to establish.

(1) The link establishment status information includes a status codefield and link configuration information of a successfully establishedlink in the links that the STA MLD requests to establish.

The status code field is used to indicate whether the STA MLD issuccessfully associated with the AP MLD. When the status code fieldindicates that the STA MLD is successfully associated with the AP MLD,the link establishment status information may carry the linkconfiguration information of the successfully established link in thelinks that the STA MLD requests to establish. When the status code fieldindicates that the STA MLD fails to be associated with the AP MLD, thelink establishment status information does not carry link configurationinformation of the links that the STA MLD requests to establish.

Whether the STA MLD is successfully associated with the AP MLD has thefollowing two interpretations.

In one interpretation, whether the STA MLD is successfully associatedwith the AP MLD is related to whether there is the successfullyestablished link in the plurality of links that the STA MLD requests toestablish. If at least one link in the plurality of links that the STAMLD requests to establish is successfully established, it indicates thatthe STA MLD is successfully associated with the AP MLD. If none of theplurality of links that the STA MLD requests to establish issuccessfully established, it indicates that the STA MLD fails to beassociated with the AP MLD.

In the other interpretation, whether the STA MLD is successfullyassociated with the AP MLD is related to whether a transmitted link inthe plurality of links that the STA MLD requests to establish issuccessfully established. In other words, only when the transmitted linkin the plurality of links that the STA MLD requests to establish issuccessfully established, it indicates that the STA MLD is successfullyassociated with the AP MLD. If the transmitted link in the plurality oflinks that the STA MLD requests to establish fails to be established, itindicates that the STA MLD fails to be associated with the AP MLD.

Therefore, in another implementation, the status code field may be usedto indicate whether the transmitted link that the STA MLD requests toestablish is successfully established, or a link establishment status ofthe transmitted link. Correspondingly, the link establishment statusinformation includes link configuration information of a successfullyestablished non-transmitted link in the links that the STA MLD requeststo establish.

A manner in which the link establishment status information is carriedin the multi-link association response frame is: The status code fieldis located in the multi-link association response frame, the linkconfiguration information of the successfully establishednon-transmitted link is located in a per link profile info field of amulti-link element, and the link configuration information of thesuccessfully established transmitted link is located in the multi-linkassociation response frame in a form of an independent field.

For example, it is assumed that a link 1 is a transmitted link, a link 2and a link 3 are non-transmitted links, and the AP MLD acceptsestablishment requests of the link 1, the link 2, and the link 3, thatis, the link 1, the link 2, and the link 3 are all successfullyestablished. As shown in FIG. 3 , in the multi-link association responseframe sent by the AP MLD, the status code field is located in themulti-link association response frame in a form of an independent field,and link configuration information of the link 2 and the link 3 islocated in the per link profile info field in the multi-link element. Inaddition, link configuration information of the link 1 is located in themulti-link association response frame in a form of an independent field.

Optionally, the status code field and the link configuration informationmay alternatively be located in another position of the associationresponse frame. This is not limited in this embodiment of thisapplication.

A status code table corresponding to the status code field is shown inTable 3. When a value of the status code field is 0, it indicates thatthe STA MLD is successfully associated with the AP MLD. That is, atleast one link in the plurality of links that the STA MLD requests toestablish is successfully established, or the transmitted link in theplurality of links that the STA MLD requests to establish issuccessfully established. When the value of the status code field is 1,it indicates that the STA MLD fails to be associated with the AP MLD.That is, none of the plurality of links that the STA MLD requests toestablish is successfully established, or the transmitted link in theplurality of links that the STA MLD requests to establish fails to beestablished. When the value of the status code field is 2, it indicatesthat TDLS is rejected, and an alternative option is provided. That is,direct link scheduling is rejected, but alternative scheduling isprovided. In other words, meanings of the status code in Table 3 are fora multi-link device, and the meanings of the status code in Table 2 arefor a single-link device.

TABLE 3 Status code table Status code Name Meaning 0 Succeed The STA MLDis successfully associated with the AP MLD 1 Rejected, and rejected foran The STA MLD fails to be associated with the unspecified reason APMLD, and a failure reason is not specified 2 TDLS is rejected, and anDirect link scheduling is rejected, but alternative option is providedalternative scheduling is provided . . . . . . . . .

One of the foregoing two optional interpretations of the status codefield by the STA MLD may be determined by using a manner of predefiningor signaling notification, to learn, based on the link establishmentstatus information, the link establishment status of each link that theSTA MLD requests to establish. In this implementation, an associationstatus of the multi-link device is represented by using the status codefield, and whether a link is successfully established is indicated basedon whether link configuration information of the link is carried. It canbe learned that, in this implementation, a link status of each link maybe indicated, and the association response frame does not need to bemodified, thereby helping improve compatibility of a protocol on a newdevice and an old device.

(2) The link establishment status information includes a status codefield and link configuration information of a successfully establishedlink in the links that the STA MLD requests to establish.

Compared with the foregoing first implementation of the linkestablishment status information, the link establishment statusinformation in this implementation is the same. A difference lies inthat the status code field is used to indicate that all or a part of theplurality of links that the STA MLD requests to establish aresuccessfully established. Optionally, the status code field indicatesthat all the links that the STA MLD requests to establish aresuccessfully established. The link establishment status information mayinclude link configuration information of all the links that the STA MLDrequests to establish.

In addition, the status code table corresponding to the status codefield further includes status code. The status code indicates that apart of the plurality of links that the STA MLD requests to establishare successfully established.

For example, as shown in the following Table 4, when the status code is0, it indicates that all of the plurality of links that the STA MLDrequests to establish are successfully established. When the status codeis 200, it indicates that a part of the links that the STA MLD requeststo establish are successfully established. That is, in Table 4, thestatus code is newly added by extending Table 2, to indicate that a partof the links are successfully established. Optionally, the newly addedstatus code may be represented by using a reserved value of the statuscode in Table 2.

TABLE 4 Status code table Status code Name Meaning 0 All links succeedAll the links that the STA MLD requests to establish are successfullyestablished 1 Rejected, and rejected for Unspecified failure anunspecified reason 2 TDLS is rejected, and an Direct link scheduling isrejected, but alternative alternative option is scheduling is providedprovided . . . . . . . . . 200 A part of the links are A part of thelinks that the STA MLD requests to successfully established establishare successfully established

Optionally, a new status code table may be predefined. The new statuscode table may include only status code indicating that all the linksthat the STA MLD requests to establish are successfully established,status code indicating that a part of the links that the STA MLDrequests to establish are successfully established, and status codeindicating that all the links that the STA MLD requests to establishfail to be established.

In addition, a manner in which the link establishment status informationis carried in the multi-link association response frame in thisimplementation is the same as that in the previous implementation, asshown in the multi-link association response frame shown in FIG. 3 .Therefore, in this implementation, in addition to the link establishmentstatus that may indicate establishment of each link, improvement on themulti-link association response frame is avoided, so that compatibilityof this implementation on different devices may be improved.

(3) The link establishment status information includes a plurality ofstatus code fields.

One status code field corresponds to one link that the STA MLD requeststo establish, and the status code field is used to indicate a linkestablishment status of the corresponding link.

In other words, a quantity of status code fields in the linkestablishment status information is equal to a quantity of links thatthe STA MLD requests to establish, to indicate the link establishmentstatus of each link by using the status code fields.

A manner in which the plurality of status code fields are carried in themulti-link association response frame may include but is not limited tothe following two implementations, which are separately described below.

(a) The status code field of each link is carried in the multi-linkassociation response frame in a manner of the status code field shown inFIG. 3 .

As shown in FIG. 9 , it is assumed that the STA MLD requests toestablish three links, which are separately a link 1, a link 2, and alink 3. A status code field of each of the three links may be located inthe multi-link association response frame in a manner shown in FIG. 9 .An arrangement order or a position of the status code field of each linkin the multi-link association response frame is not limited. Forexample, the arrangement order of the status code field of each link inthe multi-link association response frame is consistent with anarrangement order of link configuration information of links in themulti-link association response frame.

(b) A position of the status code field of each link in the multi-linkassociation response frame is related to whether the link is atransmitted link or a non-transmitted link.

A status code field of the transmitted link is the status code field inthe multi-link association response frame, namely, the status code fieldin the multi-link association response frame shown in FIG. 3 . A statuscode field of the non-transmitted link is located in a multi-linkelement in the multi-link association response frame.

In an implementation, the status code field of each non-transmitted linkmay be located in MLD-level info in the multi-link element. For example,it is assumed that the STA MLD requests to establish three links, whichare separately a link 1, a link 2, and a link 3. The link 1 is atransmitted link, and the link 2 and the link 3 are non-transmittedlinks. As shown in FIG. 10 , a status code field of the link 1 isdirectly carried in a multi-link association response frame in a form ofan independent field, and a status code field of the link 2 and a statuscode field of the link 3 are located in MLD-level info of a multi-linkelement.

In another implementation, the status code field of each non-transmittedlink may be located in the per link profile info field in the multi-linkelement. For example, it is assumed that the STA MLD requests toestablish three links, which are separately a link 1, a link 2, and alink 3. The link 1 is a transmitted link, and the link 2 and the link 3are non-transmitted links. As shown in FIG. 11 , a status code field ofthe link 1 is directly carried in a multi-link association responseframe in a form of an independent field, and a status code field of thelink 2 and a status code field of the link 3 are separately located inrespective link configuration information in a multi-link element.

In an implementation, the status code field of each link includes twopieces of optional status code, for example, first status code andsecond status code. The first status code indicates that the linkcorresponding to the status code field is successfully established, andthe second status code indicates that the link corresponding to thestatus code field fails to be established.

In another implementation, in addition to the status code indicatingwhether the link is successfully established, the optional status codeof the status code field of each link may further include one or moretypes of status code indicating “that the link fails to be establishedand a failure reason”.

In still another implementation, the optional status code of the statuscode field of each link includes but is not limited to the status codeshown in Table 2. In addition, the status code indicating an associationstatus between the STA MLD and the AP MLD in Table 2 further needs to bemodified to status code indicating a link establishment status of alink. For example, if a value of the status code field associated withthe link 1 is 0, it indicates that the link 1 is successfullyestablished. If the value of the status code field associated with thelink 1 is 2, it indicates that the link 1 requested to be established isrejected, and a rejection reason is not specified. If the value of thestatus code field associated with the link 1 is 3, it indicates that thelink 1 requested to be established is rejected by TDLS, and analternative option is provided. In other words, direct link schedulingis rejected, but alternative scheduling is provided.

Optionally, one or more of the optional status code of the status codefield of the link described in the foregoing implementations may be usedbased on signaling overheads.

(4) The link establishment status information includes a status codefield and a link establishment status bitmap.

For related descriptions of the status code field, refer to the firstand second implementations of the link establishment status information.To be specific, the status code field, as described in the firstimplementation, is used to indicate whether the STA MLD is successfullyassociated with the AP MLD. For details, refer to the content describedin the first implementation. Alternatively, the status code field, asdescribed in the second implementation, is used to indicate whether allor a part of the plurality of links requested to be established aresuccessfully established. For details, refer to the content described inthe second implementation. The following describes the linkestablishment status bitmap in detail.

In an implementation, the link establishment status bitmap is used toindicate whether each link that the STA MLD requests to establish issuccessfully established. A quantity of bits in the link establishmentstatus bitmap is equal to a total quantity of links that the STA MLDrequests to establish.

For example, the total quantity of links that the STA MLD requests toestablish is equal to N, the link establishment status bitmap comprisesN bits, and each bit corresponds to one link. If a value of a bitcorresponding to the link is equal to 1, it indicates that the link issuccessfully established. If the value of the bit corresponding to thelink is equal to 0, it indicates that the link fails to be established.

Optionally, the status code field is an independent field of themulti-link association response frame, and the link establishment statusbitmap is located in multi-link device information in a multi-linkelement in the association response frame, as shown in FIG. 12 . Thecorrespondence between each bit in the link establishment status bitmapand the link may be determined in sequence based on values of linkidentifiers.

For example, it is assumed that the STA MLD requests to establish threelinks, which are separately a link 1, a link 2, and a link 3. The linkestablishment status bitmap is three bits, and link identifiers that arearranged in ascending order are: a link identifier of the link 1, a linkidentifier of the link 2, and a link identifier of the link 3. In otherwords, the 1^(st) bit in the link establishment status bitmapcorresponds to the link 1, the 2^(nd) bit corresponds to the link 2, andthe 3^(rd) bit corresponds to the link 3. It is assumed that, as shownin FIG. 12 , the value of the status code field indicates that the STAMLD is successfully associated with the AP MLD, and the linkestablishment status bitmap is 101, it indicates that the link 1 and thelink 3 are successfully established, and the link 2 fails to beestablished.

In another implementation, if the status code field indicates, only whenthe transmitted link is successfully established, that the STA MLD issuccessfully associated with the AP MLD, or that a part of the pluralityof links that the STA MLD requests to establish are successfullyestablished, the quantity of bits in the link establishment statusbitmap may be equal to N−1. In other words, the link establishmentstatus bitmap is used to indicate whether each non-transmitted link inthe links that the STA MLD requests to establish is successfullyestablished. For example, it is assumed that a status code field shownin FIG. 14 indicates that the STA MLD is successfully associated withthe AP MLD, and a link 1 is a transmitted link. If the linkestablishment status bitmap may be 01, the link establishment statusbitmap separately indicates a link establishment status of anon-transmitted link 2 and a link establishment status of anon-transmitted link 3, that is, the link 2 fails to be established, andthe link 3 is successfully established.

In this implementation, an example in which the link establishmentstatus includes two link statuses, namely, that the link is successfullyestablished and that the link fails to be established, is used.Optionally, the link establishment status bitmap is further used toindicate another link status of each link that the STA MLD requests toestablish. In other words, a quantity of bits corresponding to each linkin the link establishment status bitmap may be determined based on atype that needs to be indicated and that is of the link status of eachlink.

In addition, a difference among the foregoing implementations of thelink establishment status information lies in that structures or contentof the link establishment status information are different, and aproblem to be resolved and a beneficial effect to be achieved are thesame. Therefore, the foregoing implementations of this embodiment ofthis application belong to a same invention concept.

It can be learned that, in this embodiment of this application,signaling overheads as low as possible can be used to indicate whethereach link that the STA MLD requests to establish is successfullyestablished, that is, a part of the links requested to be establishedbetween the STA MLD and the AP MLD are allowed to fail to beestablished, thereby greatly improving multi-link establishmentflexibility.

Embodiment 4

FIG. 13 is a schematic flowchart of the multi-link establishment method400 according to an embodiment of this application. As shown in FIG. 13, the multi-link establishment method 400 includes but is not limited tothe following steps.

S401: The STA MLD sends a reassociation request frame.

S402: The AP MLD receives the reassociation request frame.

S403: The AP MLD sends a reassociation response frame.

The AP MLD may determine the reassociation response frame based on thereassociation request frame. For example, access point-side informationthat needs to be carried in the reassociation response frame isdetermined based on station-side information carried in thereassociation request frame.

S404: The STA MLD receives the reassociation response frame, andreserves first configuration information and deletes secondconfiguration information according to a predefined rule.

The reassociation request frame is used by the STA MLD to re-initiate anassociation operation to the associated AP MLD, to help re-initiate theassociation operation when the STA MLD needs to change capabilityinformation or an associated related feature parameter. Thereassociation response frame is used to respond to the reassociationrequest frame. The reassociation request frame and the reassociationresponse frame may also carry a multi-link element.

Both the first configuration information and the second configurationinformation are configuration information stored after the STA MLD isassociated with the AP MLD. The first configuration information isconfiguration information that needs to be reserved in a reassociationoperation, and the second configuration information is configurationinformation that needs to be deleted in the reassociation operation.

For example, the first configuration information includes but is notlimited to: a block acknowledgment protocol, a sequence number, a packetnumber, a duplicate detection cache, a fragmentation and reassemblybuffer, and a buffered media access control service data unit (MSDU).The second configuration information includes but is not limited to: anenhanced distributed channel access (EDCA) function status,to-be-transmitted data in a queue, a power management mode, a wirelessnetwork management sleep mode, and the like. The buffered MSDU may alsobe referred to as an MSDU of a queue.

In an implementation, the predefined rule is used to indicateconfiguration information that needs to be reserved in the STA MLD inthe reassociation operation, that is, the predefined rule indicatescontent of the first configuration information. The second configurationinformation is other MLD-related information other than the firstconfiguration information in the STA MLD, and may be deleted by default.In another implementation, the predefined rule is used to indicateconfiguration information that needs to be deleted in the STA MLD in thereassociation operation, that is, the predefined rule indicates contentof the second configuration information. The first configurationinformation is other MLD-related information other than the secondconfiguration information in the STA MLD, and may be reserved bydefault. In still another implementation, the predefined rule is used toindicate configuration information that needs to be deleted andconfiguration information that needs to be reserved in the STA MLD inthe reassociation operation, that is, the predefined rule indicatescontent of the first configuration information and content of the secondconfiguration information. Optionally, an operation of deleting orreserving other MLD-related information other than the firstconfiguration information and the second configuration information inthe STA MLD is not limited in this embodiment of this application.

It can be learned that, in the multi-link establishment method, when theplurality of links are reestablished between the STA MLD and the AP MLDby using the reassociation request frame and the reassociation responseframe, the predefined rule may further be used to reserve a part ofconfiguration information, thereby reducing signaling overheads causedby the reassociation operation.

Optionally, the multi-link establishment methods described in Embodiment1 to Embodiment 3 may also be used with reference to thereassociation-related operation described in Embodiment 4 of thisapplication. To be specific, after the STA MLD is associated with the APMLD, if the STA MLD initiates the reassociation operation, a part ofconfiguration information may be reserved according to the foregoingdescribed implementation, to reduce signaling overheads caused by thereassociation operation.

Embodiment 5

This application further provides the multi-link establishment method500. A difference between the multi-link establishment method 500 andthe multi-link establishment method 400 lies in that, in the multi-linkestablishment method 500, reassociation information may be used toexplicitly indicate the configuration information that needs to bereserved in the reassociation operation between the STA MLD and the APMLD. Refer to a schematic flowchart of the multi-link establishmentmethod 500 shown in FIG. 14 . The multi-link establishment method 500includes but is not limited to the following steps.

S501: The STA MLD sends a reassociation request frame.

S502: The AP MLD receives the reassociation request frame.

S503: The AP MLD sends a reassociation response frame to the STA MLD,where the reassociation response frame carries reassociationinformation, and the reassociation information is used to indicatewhether each parameter in association configuration information isreserved.

Optionally, the reassociation response frame carries reassociationinformation, and the reassociation information is used to indicatewhether each parameter in association configuration information isdeleted. Optionally, the reassociation information may also be referredto as configuration information update information, or the like. Thename is not limited in this embodiment of this application.

The association configuration information is stored by the STA MLD afterthe STA MLD is associated with the access point multi-link device APMLD. Optionally, the association configuration information is a part orall of configuration information stored by the STA MLD after the STA MLDis associated with the AP MLD. Optionally, the parameter included in theassociation configuration information is predefined, or is notified bythe AP MLD by using signaling. For example, the associationconfiguration information includes but is not limited to: a blockacknowledgment protocol, a sequence number, a packet number, a duplicatedetection cache, a fragmentation and reassembly buffer, and a bufferedmedia access control service data unit (MSDU).

For example, the association configuration information may include onlyconfiguration information that needs to be considered whether to bereserved in the reassociation operation, and configuration information,other than the association configuration information, stored by the STAMLD may be deleted by default. For example, the associationconfiguration information may include only configuration informationthat needs to be considered whether to be deleted in the reassociationoperation, and configuration information, other than the associationconfiguration information, stored by the STA MLD may be reserved bydefault.

S504: The STA MLD receives the reassociation response frame.

The reassociation request frame is used by the STA MLD to re-initiate anassociation operation to the associated AP MLD, to help re-initiate theassociation operation when the STA MLD needs to change capabilityinformation or an associated related feature parameter. Thereassociation response frame is used to respond to the reassociationrequest frame. The reassociation request frame and the reassociationresponse frame may also carry a multi-link element.

In an implementation, the reassociation information includes one or morebits. One bit corresponds to one or more parameters in the associationconfiguration information, and the bit is used to indicate whether thecorresponding one or more parameters are reserved.

For example, when a value of the bit is a first value, it indicates thatthe one or more parameters corresponding to the bit are reserved. Whenthe value of the bit is a second value, it indicates that the one ormore parameters corresponding to the bit are deleted. The first valuemay be 1, the second value may be 0, and vice versa. Specifically, theone or more parameters, corresponding to each bit in the reassociationinformation, in the association configuration information may bepredefined or learned by using signaling.

A manner in which the reassociation information is carried in thereassociation response frame includes but is not limited to thefollowing three manners. A first carrying manner is: The reassociationinformation is carried in the reassociation response frame in a mannerof a reassociation element. A second carrying manner is: Thereassociation information is carried, in a manner of a reassociationfield, in multi-link device information in a multi-link element in thereassociation response frame. A third carrying manner is: Thereassociation information is carried in the reassociation response framein a manner of an independent field. The following describes the mannersin detail.

(1) The reassociation information is carried in the reassociationresponse frame in a manner of a reassociation element.

The reassociation element may also be referred to as a configurationinformation indication element, or the like in the reassociationresponse frame. This is not limited in this embodiment of thisapplication. Optionally, a structure of the reassociation element isshown in FIG. 15 and FIG. 16 . The reassociation element is carried inthe reassociation response frame, and includes an element identifier(element ID), a length, and reassociation information. A quantity ofbytes or bits occupied by the element identifier, a quantity of bytes orbits occupied by the length, and a quantity of bytes or bits occupied bythe reassociation information may be predefined. The element identifieris used to indicate that the element is the reassociation element. Thelength is used to indicate a total quantity of bits or bytes between astart of a bit occupied by the length field to an end of a bit occupiedby the reassociation information.

In one case, the reassociation information includes a plurality of bits.One bit corresponds to one parameter in the association configurationinformation, and is used to indicate whether the corresponding parameteris reserved.

For example, as shown in FIG. 15 , it is assumed that the reassociationinformation is six bits, and the six bits are respectively in aone-to-one correspondence with a block acknowledgment protocol, asequence number, a packet number, a duplicate detection cache, afragmentation and reassembly buffer, and a buffered MSDU in theassociation configuration information. Assuming that the reassociationinformation read by the STA MLD from the reassociation response frame is100001, the STA MLD may reserve the block acknowledgment protocol andthe buffered MSDU in the STA MLD, and deletes the sequence number, thepacket number, the duplicate detection cache, the fragmentation andreassembly buffer in the STA MLD.

In another case, the reassociation information includes a plurality ofbits. One bit corresponds to one or more parameters in the associationconfiguration information, and the bit is used to indicate whether thecorresponding one or more parameters are reserved.

For example, as shown in FIG. 16 , the reassociation information is twobits. The 1^(st) bit corresponds to a block acknowledgment protocol, asequence number, a packet number, a duplicate detection cache, and afragmentation and reassembly buffer in the association configurationinformation, and is used to indicate whether the block acknowledgmentprotocol, the sequence number, the packet number, the duplicatedetection cache, and the fragmentation and reassembly buffer arereserved. The 2^(nd) bit corresponds to a buffered MSDU in theassociation configuration information, and is used to indicate whetherthe buffered MSDU is reserved. Assuming that the reassociationinformation read by the STA MLD from the reassociation response frame is11, the STA MLD may reserve the block acknowledgment protocol, thesequence number, the packet number, the duplicate detection cache, thefragmentation and reassembly buffer, and the buffered MSDU in the STAMLD.

(2) The reassociation information is carried, in a manner of areassociation field, in MLD-level info in a multi-link element in thereassociation response frame.

The reassociation information may be referred to as a reassociationdomain, a reassociation field, or the like in the multi-link element inthe reassociation response frame. For example, a structure of thereassociation information in the reassociation response frame is shownin FIG. 17 and FIG. 18 . The reassociation information is carried in themulti-link device information (MLD-level info) in the reassociationresponse frame. A quantity of bytes or bits occupied by thereassociation information may be predefined or notified by usingsignaling. For example, for the reassociation information shown in FIG.17 or FIG. 18 , it is assumed that the quantity of bits occupied by thereassociation information is six bits as shown in FIG. 17 , or two bitsas shown in FIG. 18 .

In an implementation, the reassociation information may be carried onlyin the reassociation response frame. In another implementation, inaddition to being carried in the reassociation response frame, thereassociation information may alternatively be carried in thereassociation request frame. The reassociation information carried inthe reassociation request frame may also have the features described inthe foregoing implementations. A difference between the reassociationinformation carried in the reassociation request frame and thereassociation information carried in the reassociation response framelies in that, the reassociation information carried in the reassociationrequest frame is used to indicate whether each parameter, requested bythe STA MLD, in the association configuration information in thereassociation operation between the STA MLD and the AP MLD is reserved,and the reassociation information carried in the reassociation responseframe is used to indicate each parameter, requested by the AP MLD to bereserved by the STA MLD, in the association configuration information inthe reassociation operation between the STA MLD and the AP MLD isreserved.

Optionally, in addition to reserving a part of the parameters in theassociation configuration information and deleting the other part of theparameters in the association configuration information based on thereassociation information, the STA MLD may delete or reserveconfiguration information other than the association configurationinformation in the STA MLD by default. This is not limited in thisembodiment of this application.

It can be learned that, in the multi-link establishment method 400, inthe reassociation process, the parameter that needs to be reserved isexplicitly indicated by using the reassociation information, therebyreducing signaling overheads caused by reassociation, and improvingflexibility of notifying the STA MLD of the parameter that needs to bereserved.

Optionally, the multi-link establishment methods described in Embodiment1 to Embodiment 3 may also be used with reference to thereassociation-related operation described in Embodiment 5 of thisapplication. To be specific, after the STA MLD is associated with the APMLD, if the STA MLD initiates the reassociation operation, a part ofconfiguration information may be reserved according to the foregoingdescribed implementation, to reduce signaling overheads caused by thereassociation operation.

In the foregoing embodiments provided in this application, the methodsprovided in the embodiments of this application are separately describedfrom perspectives of the AP MLD and the STA MLD. To implement functionsin the methods provided in the foregoing embodiments of thisapplication, the AP MLD and the STA MLD each may include a hardwarestructure and a software module, to implement the foregoing functions ina form of the hardware structure, the software module, or a combinationof the hardware structure and the software module. A function in theforegoing functions may be performed in a manner of the hardwarestructure, the software module, or a combination of the hardwarestructure and the software module. The following describes communicationapparatuses in the embodiments of this application with reference toFIG. 19 to FIG. 21 . The communication apparatus is an access point inan access point multi-link device or a station in a station multi-linkdevice. Further, the communication apparatus may be an apparatus in anAP MLD, or an apparatus in a STA MLD. In addition, the apparatus may bea multi-link device, an apparatus in the multi-link device, or aprocessor or a chip system in the multi-link device.

A communication apparatus 100 shown in FIG. 19 may include acommunication unit 101 and a processing unit 102. The processing unit102 is configured to process data. The communication unit 101 isintegrated with a receiving unit and a sending unit. The communicationunit 101 may also be referred to as a transceiver unit. Alternatively,the communication unit 101 may be split into a receiving unit and asending unit. Specifically:

When the communication apparatus shown in FIG. 19 is configured toperform the method performed by the STA MLD in the method embodimentdescribed in FIG. 4 :

The processing unit 102 is configured to determine a multi-linkassociation request frame; and

the communication unit 101 is configured to send the multi-linkassociation request frame, where

the communication unit 101 is further configured to receive a multi-linkassociation response frame, and

the multi-link association response frame carries radio bitmapinformation, and the radio bitmap information is used to indicate aradio, allowed to be used to establish each link that the STA MLDrequests to establish, of the STA MLD.

When the communication apparatus shown in FIG. 19 is configured toperform the AP MLD the method performed by in the method embodimentdescribed in FIG. 4 :

the communication unit 101 is configured to receive a multi-linkassociation request frame; and

the processing unit 102 is configured to determine a multi-linkassociation response frame, wherein

the communication unit 101 is further configured to send the multi-linkassociation response frame, and

the multi-link association response frame carries radio bitmapinformation, and the radio bitmap information is used to indicate aradio, allowed to be used to establish each link that a STA MLD requeststo establish, of the STA MLD.

Applicable to the STA MLD and the AP MLD in the method embodimentdescribed in FIG. 4 , the radio bitmap information is carried inmulti-link device information in a multi-link element.

When the communication apparatus shown in FIG. 19 is configured toperform the STA MLD the method performed by in the method embodimentdescribed in FIG. 6 :

The processing unit 102 is configured to determine a multi-linkassociation request frame; and

the communication unit 101 is configured to send the multi-linkassociation request frame, where

the communication unit 101 is further configured to receive a multi-linkassociation response frame, and

the multi-link association response frame carries a plurality of piecesof radio bitmap information, one piece of radio bitmap informationcorresponds to one link that the STA MLD requests to establish, and theradio bitmap information is used to indicate a radio, allowed to be usedto establish the corresponding link, of the STA MLD.

When the communication apparatus shown in FIG. 19 is configured toperform the AP MLD the method performed by in the method embodimentdescribed in FIG. 6 :

the communication unit 101 is configured to receive a multi-linkassociation request frame; and

the processing unit 102 is configured to determine a multi-linkassociation response frame, wherein

the communication unit 101 is further configured to send the multi-linkassociation response frame, and

the multi-link association response frame carries a plurality of piecesof radio bitmap information, one piece of radio bitmap informationcorresponds to one link that a STA MLD requests to establish, and theradio bitmap information is used to indicate a radio, allowed to be usedto establish the corresponding link, of the STA MLD.

Applicable to the STA MLD and the AP MLD in the method embodimentdescribed in FIG. 6 , as shown in the related content in FIG. 7 , radiobitmap information of a transmitted link that the STA MLD requests toestablish is carried in multi-link device information in a multi-linkelement in the multi-link association response frame; and radio bitmapinformation of a non-transmitted link that the STA MLD requests toestablish is carried in link configuration information of thenon-transmitted link in the multi-link element.

Applicable to the STA MLDs and the AP MLDs in the method embodimentsdescribed in FIG. 4 and FIG. 6 , the multi-link association requestframe carries radio quantity information, and the radio quantityinformation is used to indicate a quantity of radios of the STA MLD.

When the communication apparatus shown in FIG. 19 is configured toperform the STA MLD the method performed by in the method embodimentdescribed in FIG. 8 :

the communication unit 101 is configured to send the multi-linkassociation request frame, where

the communication unit 101 is further configured to receive a multi-linkassociation response frame, and

the multi-link association response frame carries link establishmentstatus information, and the link establishment status information isused to indicate a link establishment status of each link that the STAMLD requests to establish.

When the communication apparatus shown in FIG. 19 is configured toperform the AP MLD the method performed by in the method embodimentdescribed in FIG. 8 :

the communication unit 101 is configured to receive a multi-linkassociation request frame, where

the communication unit 101 is further configured to send a multi-linkassociation response frame, and

the multi-link association response frame carries link establishmentstatus information, and the link establishment status information isused to indicate a link establishment status of each link that a STA MLDrequests to establish.

The following describes one or more implementations applicable to theSTA MLD and the AP MLD in the method embodiment described in FIG. 8 .

In an implementation, the link establishment status information includesa status code field and link configuration information of a successfullyestablished link in the links that the STA

MLD requests to establish. The status code field is used to indicatethat the STA MLD is successfully associated with the AP MLD.

In another implementation, the link establishment status informationincludes a status code field and link configuration information of asuccessfully established link in the links that the STA MLD requests toestablish; and

the status code field is used to indicate that a part of the links thatthe STA MLD requests to establish are successfully established.

In still another implementation, the link establishment statusinformation includes a status code field and link configurationinformation of a successfully established non-transmitted link in thelinks that the STA MLD requests to establish; and

the status code field is used to indicate that a transmitted link in thelinks that the STA MLD requests to establish is successfullyestablished.

In still another implementation, the link establishment statusinformation includes a plurality of status code fields, and one statuscode field corresponds to one link that the STA MLD requests toestablish; and

the status code field is used to indicate a link establishment status ofthe corresponding link.

In still another implementation, in the links that the STA MLD requeststo establish, a status code field of a transmitted link is carried inmulti-link device information in a multi-link element, and a status codefield of a non-transmitted link is carried in link configurationinformation of the non-transmitted link in the multi-link element; or inthe links that the STA MLD requests to establish, status code fields ofall the links are carried in multi-link device information in amulti-link element.

In still another implementation, the link establishment statusinformation includes a status code field and link establishment statusbitmap information, and the status code field is used to indicate thatthe STA MLD is successfully associated with the AP MLD; and

the link establishment status bitmap information is used to indicatewhether each link that the STA MLD requests to establish is successfullyestablished.

In still another implementation, the link establishment statusinformation includes a status code field and link establishment statusbitmap information;

the status code field is used to indicate that a part of the links thatthe STA MLD requests to establish are successfully established; and

the link establishment status bitmap information is used to indicatewhether each link that the STA MLD requests to establish is successfullyestablished.

In still another implementation, the link establishment statusinformation includes a status code field and link establishment statusbitmap information;

the status code field is used to indicate that a transmitted link in thelinks that the STA MLD requests to establish is successfullyestablished; and

the link establishment status bitmap information is used to indicatewhether each non-transmitted link that the STA MLD requests to establishis successfully established.

In still another implementation, the link establishment status bitmapinformation is carried in multi-link device information in a multi-linkelement in the multi-link association response frame.

In still another implementation, when the communication apparatus shownin FIG. 19 is configured to perform the STA MLD the method performed byin the method embodiment described in FIG. 13 :

the communication unit 101 is further configured to send a reassociationrequest frame, and

the communication unit 101 is further configured to receive areassociation response frame; and

the processing unit 102 is configured to reserve first configurationinformation and delete second configuration information according to apredefined rule.

In still another implementation, when the communication apparatus shownin FIG. 19 is configured to perform the STA MLD the method performed byin the method embodiment described in FIG. 14 :

the communication unit 101 is further configured to send a reassociationrequest frame, and

the communication unit 101 is further configured to receive areassociation response frame; and

the reassociation response frame carries reassociation information, andthe reassociation information is used to indicate whether each parameterin association configuration information is reserved.

When the communication apparatus shown in FIG. 19 is configured toperform the AP MLD the method performed by in the method embodimentdescribed in FIG. 14 :

the communication unit is further configured to receive a reassociationrequest frame, and

the communication unit is further configured to send a reassociationresponse frame, where

the reassociation response frame carries reassociation information, andthe reassociation information is used to indicate whether each parameterin association configuration information is reserved.

The following describes one or more implementations applicable to theSTA MLD and the AP MLD in the method embodiment described in FIG. 14 .

In an implementation, the association configuration information includesone or more of the following parameters:

a block acknowledgment protocol, a sequence number, a packet number, aduplicate detection cache, a fragmentation and reassembly buffer, and abuffered media access control service data unit MSDU.

In an implementation, the reassociation information includes one or morebits. One bit corresponds to one or more parameters in the associationconfiguration information, and the bit is used to indicate whether thecorresponding one or more parameters are reserved.

In an implementation, the reassociation information is carried inmulti-link device information in a multi-link element in thereassociation response frame.

FIG. 20 is a schematic block diagram of a communication apparatus 200.In an implementation, the communication apparatus 200 corresponds to theAP MLD applicable to any one of the multi-link establishment method 100to the multi-link establishment method 500. Optionally, thecommunication apparatus 200 may be the station 101 in FIG. 1 , or the APMLD in FIG. 2 . Optionally, the communication apparatus 200 is a chip, achip system, a processor, or the like that implements the foregoingmethod embodiments. The communication apparatus 200 may be configured toimplement the methods described in the foregoing method embodiments. Fordetails, refer to the descriptions in the foregoing method embodiments.

In another implementation, the communication apparatus 200 correspondsto the STA MLD applicable to any one of the multi-link establishmentmethod 100 to the multi-link establishment method 500. Alternatively,the communication apparatus 200 is the station 102 in FIG. 1 or anapparatus thereof. Alternatively, the communication apparatus 200 is theSTA MLD in FIG. 2 . Optionally, the communication apparatus 200 is achip, a chip system, a processor, or the like that implements theforegoing method embodiments. The communication apparatus 200 may beconfigured to implement the methods described in the foregoing methodembodiments. For details, refer to the descriptions in the foregoingmethod embodiments.

The communication apparatus 200 may include one or more processors 201.The processor 201 may be a general purpose processor, a dedicatedprocessor, or the like. For example, the processor 201 may be a basebandprocessor or a central processing unit. The baseband processor may beconfigured to process a communication protocol and communication data,and the central processing unit may be configured to control acommunication apparatus (for example, a base station, a baseband chip, aterminal, a terminal chip, a DU, or a CU) to execute a computer program,to process data of the computer program.

The communication apparatus 200 may further include a transceiver 205.The transceiver 205 may be referred to as a transceiver unit, atransceiver, a transceiver circuit, or the like, and is configured toimplement a transceiver function. The transceiver 205 may include areceiver and a transmitter. The receiver may be referred to as areceiver machine, a receiver circuit, or the like, and is configured toimplement a receiving function. The transmitter may be referred to as atransmitter machine, a transmitter circuit, or the like, and isconfigured to implement a sending function. Optionally, thecommunication apparatus 200 may further include an antenna 206.

Optionally, the communication apparatus 200 may include one or morememories 202, and the memory 202 may store instructions 204. Theinstructions 204 may be a computer program. The computer program may berun on the communication apparatus 200, to enable the communicationapparatus 200 to perform the methods described in the foregoing methodembodiments. Optionally, the memory 202 may further store data. Thecommunication apparatus 200 and the memory 202 may be separatelydisposed, or may be integrated.

When the communication apparatus 200 is configured to implement afunction of the STA MLD in any one of the multi-link establishmentmethod 100 to the multi-link establishment method 500 in the foregoingmethod embodiments:

the processor 201 may be configured to determine a multi-linkassociation request frame.

The transceiver 205 is configured to perform steps S101 and S104 in FIG.4 ; steps S201 and S204 in FIG. 6 ; steps S301 and S304 in FIG. 8 ;steps S401 and S404 in FIG. 13 ; or steps S501 and S504 in FIG. 14 .

When the communication apparatus 200 is configured to implement afunction of the AP MLD in any one of the multi-link establishment method100 to the multi-link establishment method 500 in the foregoing methodembodiments:

the processor 201 may be configured todetermine a multi-link associationresponse frame.

The transceiver 205 is configured to perform steps S102 and S103 in FIG.4 ; steps S202 and S203 in FIG. 6 ; steps S302 and S303 in FIG. 8 ;steps S402 and S403 in FIG. 13 ; or steps S502 and S503 in FIG. 14 .

In an implementation, the processor 201 may include a transceiverconfigured to implement a receiving function and a sending function. Forexample, the transceiver may be a transceiver circuit, an interface, oran interface circuit. A transceiver circuit, an interface, or aninterface circuit configured to implement the sending function and atransceiver circuit, an interface, or an interface circuit configured toimplement the receiving function may be separated, or may be integrated.The transceiver circuit, the interface, or the interface circuit may beconfigured to read and write code or data. Alternatively, thetransceiver circuit, the interface, or the interface circuit may beconfigured to transmit or transfer a signal.

In an implementation, the processor 201 may store instructions 203. Theinstructions may be a computer program. The computer program 203 is runon the processor 201, to enable the communication apparatus 200 toperform the methods described in the foregoing method embodiments. Thecomputer program 203 may be fixed in the processor 201, and in thiscase, the processor 201 may be implemented by hardware.

In an implementation, the communication apparatus 200 may include acircuit, and the circuit may implement a sending, receiving, orcommunication function in the foregoing method embodiments. Theprocessor and the transceiver described in this application may beimplemented in an integrated circuit (IC), an analog IC, a radiofrequency integrated circuit RFIC, a mixed-signal IC, anapplication-specific integrated circuit (ASIC), or a printed circuitboard (PCB), an electronic device, and the like. The processor and thetransceiver may alternatively be manufactured by using various ICprocess technologies, for example, a complementary metal oxidesemiconductor (CMOS), an n-type metal oxide semiconductor (NMOS), ap-type metal oxide semiconductor (PMOS), a bipolar junction transistor(BJT), a bipolar CMOS (BiCMOS), silicon germanium (SiGe), and galliumarsenide (GaAs).

The communication apparatus described in the foregoing embodiment may bean AP MLD or an AP in the AP MLD. However, a scope of the communicationapparatus described in this application is not limited thereto, and astructure of the communication apparatus may not be limited by FIG. 20 .The communication apparatus may be an independent device or may be apart of a relatively large device. For example, the communicationapparatus may be:

(1) an independent integrated circuit IC, a chip, or a chip system orsubsystem;

(2) a set including one or more ICs, where optionally, the IC set mayfurther include a storage component configured to store data and acomputer program;

(3) an ASIC, for example, a modem (Modem);

(4) a module that can be embedded in another device;

(5) a receiver, a terminal, an intelligent terminal, a cellular phone, awireless device, a handheld device, a mobile unit, a vehicle-mounteddevice, a network device, a cloud device, an artificial intelligencedevice, or the like; or

(6) others, or the like.

For a case in which the communication apparatus may be a chip or a chipsystem, refer to a schematic diagram of a structure of a chip shown inFIG. 21 . The chip shown in FIG. 21 includes a processor 301 and aninterface 302. There may be one or more processors 301, and there may bea plurality of interfaces 302.

When the chip is configured to implement a function of an AP in the APMLD in any one of the multi-link establishment method 200 to themulti-link establishment method 500 in the foregoing method embodiments:

the processor 301 may determine a multi-link association request frame.

The interface 302 is configured to perform steps S101 and S104 in FIG. 4; steps S201 and S204 in FIG. 6 ; steps S301 and S304 in FIG. 8 ; stepsS401 and S404 in FIG. 13 ; or steps S501 and S504 in FIG. 14 .

When the chip is configured to implement a function of an AP in the APMLD in any one of the multi-link establishment method 100 to themulti-link establishment method 500 in the foregoing method embodiments:

the processor 301 may determine a multi-link association response frame.

The interface 302 is configured to perform steps S102 and S103 in FIG. 4; steps S202 and S203 in FIG. 6 ; steps S302 and S303 in FIG. 8 ; stepsS402 and S403 in FIG. 13 ; or steps S502 and S503 in FIG. 14 .

A person skilled in the art may further understand that variousillustrative logical blocks and steps (step) that are listed in theembodiments of this application may be implemented by using electronichardware, computer software, or a combination thereof Whether thefunctions are implemented by using hardware or software depends onparticular applications and a design requirement of the entire system. Aperson skilled in the art may use various methods to implement thedescribed functions for each particular application, but it should notbe considered that the implementation goes beyond the scope of theembodiments of this application.

This application further provides a computer-readable storage medium.The computer-readable storage medium stores a computer program, and whenthe computer-readable storage medium is executed by a computer, afunction of any one of the foregoing method embodiments is implemented.

This application further provides a computer program product. When thecomputer program product is executed by a computer, a function of anyone of the foregoing method embodiments is implemented.

All or some of the foregoing embodiments may be implemented by usingsoftware, hardware, firmware, or any combination thereof When softwareis used for implementation, all or some of the embodiments may beimplemented in a form of a computer program product. The computerprogram product includes one or more computer programs. When thecomputer program is loaded and executed on a computer, the procedures orfunctions according to the embodiments of this application are all orpartially generated. The computer may be a general-purpose computer, adedicated computer, a computer network, or another programmableapparatus. The computer program may be stored in a computer-readablestorage medium or may be transmitted from a computer-readable storagemedium to another computer-readable storage medium. For example, thecomputer program may be transmitted from a website, computer, server, ordata center to another website, computer, server, or data center in awired (for example, a coaxial cable, an optical fiber, or a digitalsubscriber line (DSL)) or wireless (for example, infrared, radio, ormicrowave) manner. The computer-readable storage medium may be anyusable medium accessible by a computer, or a data storage device, suchas a server or a data center, integrating one or more usable media. Theusable medium may be a magnetic medium (for example, a floppy disk, ahard disk, or a magnetic tape), an optical medium (for example, a highdensity digital video disc (DVD)), a semiconductor medium (for example,a solid-state drive (SSD)), or the like.

A person of ordinary skill in the art may understand that variousreference numerals such as “first” and “second” in this application aremerely used for differentiation for ease of description, and are notused to limit a scope of the embodiments of this application, orrepresent a sequence.

“The at least one” in this application may alternatively be described asone or more, and “the plurality of” means two, three, four, or more.This is not limited in this application. In the embodiments of thisapplication, “first”, “second”, “third”, “A”, “B”, “C”, “D”, and thelike are used for distinguishing between technical features described bythem. There is no chronological order or no size order between thetechnical features described by “first”, “second”, “third”, “A”, “B”,“C”, and “D”.

The correspondences shown in the tables in this application may beconfigured, or may be predefined. Values of the information in thetables are merely examples, and other values may be configured. This isnot limited in this application. When a correspondence betweeninformation and each parameter is configured, not all correspondencesshown in the tables need to be configured. For example, in the tables inthis application, correspondences shown in some rows may alternativelynot be configured. For another example, proper deformations andadjustments such as splitting and combination may be performed based onthe foregoing tables. Names of the parameters shown in titles of theforegoing tables may alternatively be other names that can be understoodby a communication apparatus, and values or representation manners ofthe parameters may alternatively be other values or representationmanners that can be understood by the communication apparatus. Duringimplementation of the foregoing tables, another data structure, such asan array, a queue, a container, a stack, a linear table, a pointer, alinked list, a tree, a graph, a structure, a class, a pile, or a hashtable, may alternatively be used.

“Predefine” in this application may be understood as “define”,“predefine”, “store”, “pre-store”, “pre-negotiate”, “pre-configure”,“solidify”, or “pre-burn”.

A person of ordinary skill in the art may be aware that, in combinationwith the examples described in the embodiments disclosed in thisspecification, units and algorithm steps may be implemented byelectronic hardware or a combination of computer software and electronichardware. Whether the functions are performed by the hardware or thesoftware depends on particular applications and design constraints ofthe technical solutions. A person skilled in the art may use differentmethods to implement the described functions for each particularapplication, but it should not be considered that the implementationgoes beyond the scope of this application.

It may be clearly understood by a person skilled in the art that for thepurpose of convenient and brief description, for a detailed workingprocess of the described systems, apparatuses, and units, refer to acorresponding process in the foregoing method embodiment.

The foregoing descriptions are merely specific implementations of thisapplication, but are not intended to limit the protection scope of thisapplication. Any variation or replacement readily figured out by aperson skilled in the art within the technical scope disclosed in thisapplication shall fall within the protection scope of this application.Therefore, the protection scope of this application shall be subject tothe protection scope of the claims.

What is claimed is:
 1. A communication apparatus, used in a stationmulti-link device (STA MLD), wherein the communication apparatuscomprises: a processor coupled to a memory configured to store programinstructions for execution by the processor, wherein when executing theprogram instructions, the communication apparatus is configured to: senda multi-link association request frame; and receive a multi-linkassociation response frame; wherein the multi-link association responseframe carries link establishment status information, and the linkestablishment status information is used to indicate link establishmentstatuses of at least two links that the STA MLD requests to establish.2. The communication apparatus according to claim 1, wherein the linkestablishment status information comprises at least two status codefields, and one of the status code fields is used to indicate anestablishment status of one of the at least two links that the STA MLDrequests to establish.
 3. The communication apparatus according to claim1, wherein the at least two links that the STA MLD requests to establishcomprise a transmitted link and at least one non-transmitted link, thetransmitted link is a link on which the multi-link association requestframe is transmitted, and the non-transmitted link is a link other thanthe link on which the multi-link association request frame istransmitted.
 4. The communication apparatus according to claim 3,wherein the multi-link association response frame comprises a multi-linkelement, and the multi-link element comprises multi-link deviceinformation and link configuration information of the at least onenon-transmitted link.
 5. The communication apparatus according to claim4, wherein a status code field of the non-transmitted link is carried inthe link configuration information of the non-transmitted link.
 6. Thecommunication apparatus according to claim 4, wherein a status codefield of the transmitted link is carried in the multi-link associationresponse frame.
 7. The communication apparatus according to claim 4,wherein the link configuration information comprises a link identifier.8. The communication apparatus according to claim 7, wherein the linkidentifier is indicates a value of a link, and the link configurationinformation indicates information related to the link.
 9. A multi-linkestablishment method, used in a station multi-link device (STA MLD),wherein the method comprises: sending a multi-link association requestframe; and receiving a multi-link association response frame, whereinthe multi-link association response frame carries link establishmentstatus information, and the link establishment status information isused to indicate link establishment statuses of at least two links thatthe STA MLD requests to establish.
 10. The method according to claim 9,wherein the link establishment status information comprises at least twostatus code fields, and one of the status code fields is used toindicate an establishment status of one of the at least two links thatthe STA MLD requests to establish.
 11. The method according to claim 9,wherein the at least two links that the STA MLD requests to establishcomprise a transmitted link and at least one non-transmitted link, thetransmitted link is a link on which the multi-link association requestframe is transmitted, and the non-transmitted link is a link other thanthe link on which the multi-link association request frame istransmitted.
 12. The method according to claim 11, wherein themulti-link association response frame comprises a multi-link element,and the multi-link element comprises multi-link device information andlink configuration information of the at least one non-transmitted link.13. The method according to claim 12, wherein a status code field of thenon-transmitted link is carried in the link configuration information ofthe non-transmitted link.
 14. The method according to claim 12, whereina status code field of the transmitted link is carried in the multi-linkassociation response frame.
 15. The method according to claim 12,wherein the link configuration information comprises a link identifier.16. The method according to claim 15, wherein the link identifier isindicates a value of a link, and the link configuration informationindicates information related to the link.
 17. A chip, comprising aninterface and a processor, wherein the interface is coupled to theprocessor, wherein the processor is configured to: send a multi-linkassociation request frame; and receive a multi-link association responseframe; wherein the multi-link association response frame carries linkestablishment status information, and the link establishment statusinformation is used to indicate link establishment statuses of at leasttwo links that the chip requests to establish.
 18. The chip according toclaim 17, wherein the link establishment status information comprises atleast two status code fields, and one of the status code fields is usedto indicate an establishment status of one of the at least two linksthat the chip requests to establish.
 19. The chip according to claim 17,wherein the at least two links that the chip requests to establishcomprise a transmitted link and at least one non-transmitted link, thetransmitted link is a link on which the multi-link association requestframe is transmitted, and the non-transmitted link is a link other thanthe link on which the multi-link association request frame istransmitted.
 20. The chip according to claim 19, wherein the multi-linkassociation response frame comprises a multi-link element, and themulti-link element comprises multi-link device information and linkconfiguration information of the at least one non-transmitted link. 21.The chip according to claim 20, wherein a status code field of thenon-transmitted link is carried in the link configuration information ofthe non-transmitted link.
 22. The chip according to claim 20, wherein astatus code field of the transmitted link is carried in the multi-linkassociation response frame.
 23. The chip according to claim 20, whereinthe link configuration information comprises a link identifier, whereinthe link identifier indicates a value of a link, and the linkconfiguration information indicates related information of the link. 24.A non-transitory computer-readable media storing computer instructions,that when executed by one or more processors of a station multi-linkdevice (STA MLD), cause the one or more processors to perform the stepsof: send a multi-link association request frame; and receive amulti-link association response frame; wherein the multi-linkassociation response frame carries link establishment statusinformation, and the link establishment status information is used toindicate link establishment statuses of at least two links that the STAMLD requests to establish.
 25. The non-transitory computer-readablemedia according to claim 24, wherein the link establishment statusinformation comprises at least two status code fields, and one of thestatus code fields is used to indicate an establishment status of one ofthe at least two links that the STA MLD requests to establish.
 26. Thenon-transitory computer-readable media according to claim 24, whereinthe at least two links that the STA MLD requests to establish comprise atransmitted link and at least one non-transmitted link, the transmittedlink is a link on which the multi-link association request frame istransmitted, and the non-transmitted link is a link other than the linkon which the multi-link association request frame is transmitted. 27.The non-transitory computer-readable media according to claim 26,wherein the multi-link association response frame comprises a multi-linkelement, and the multi-link element comprises multi-link deviceinformation and link configuration information of the at least onenon-transmitted link.
 28. The non-transitory computer-readable mediaaccording to claim 27, wherein a status code field of thenon-transmitted link is carried in the link configuration information ofthe non-transmitted link.
 29. The non-transitory computer-readable mediaaccording to claim 28, wherein a status code field of the transmittedlink is carried in the multi-link association response frame.
 30. Thenon-transitory computer-readable media according to claim 27, whereinthe link configuration information comprises a link identifier, whereinthe link identifier indicates a value of a link, and the linkconfiguration information indicates related information of the link.